I feel the difference is that the Fantastic Four are all heroes themselves, so they are more able to defend themselves, where-as Aunt May and Mary Jane are not. The fantastic Four are also heroes full-time. Spider-Man usually has to make a living on the side like the average middle-class citizen and having his identity as Spider-Man known may compromise that.

G-man, I can see where you are going with this, but in the case of The FF vs. Spider-man. Reed Richards isn't the only one who has superpowers so therefore he can afford to reveal his secret identity. He is part of a team and as a matter of fact even his children has super-powers to protect them for appending doom. With Spider-man's family, Aunt May in particular doesn't (and shouldn't) have super-powers (so don't get any funny ideas Mr. Quesada). So in Spider-man's situation a secret identity is a must. If I had a super-power, I would definitely have a secret identity, not only to protect my family but I really wouldn't want people know who I am and call me every time something happened like getting their cat out of atree.

well theres the difference right there the fantastic four went public from day one, at the begining they didnt have anyone to put in danger except themselves no immidiate family around to threaten no kids yet for them it was fine. but spidey from the very begining strived for secrecy his uncle had gotten killed because of his ignorence and that was the main drive to me for him to keep his identity to himself. not to mention at the time he was 15 years old , and when you're that age its pretty much law for you to keep things hidden especially if you're able to stick to the ceiling. if he went public from day one mabye things would have been different i dont know theres never been a "what if spider-man never had a secret identity" issue 
 
and if i had superpowers, i'd definitly have a secret identity. mainly cause i'd be doin a whole bunch of bad s***

People like the Fantastic 4 don't need their identities secret because, their pretty much invincible because they work as a team, and their all family. Characters like Spider-man work solo, he does not have a team if he tells the world(again) that he is spider-man the same thing will probably happen just like in back in black, etc. X-men, X-force, etc, they don't need their identities safe, they are a team. Strength comes in numbers, who is going to mess with a person that has a whole team backing them up? No one! That is why the villains go after the solo's. Wolverine acts like he works alone, but really he has the x-men backing him up. Sure he can get himself out of anything, and he does not have anything to loose, but it is like "if you mess with him, you mess with all of us." Another good example is Hulk.  
 
He is naturally a lone wolf. Hulk has had many friends, Rick Jones, Doc Samson, She-hulk, and others. However, he has always had to fight his battles on his own. Yeah the Hulk is a unstoppable force, but who is really the friend of the hulk? I don't think that heroes should reveal their identities under pressure. This makes their character feel like a last resort. Spider-man has gone through lots of things, but to reveal his identity during the civil war? He should have began joining Cap's secret rebellion. Heroes that already have their identity known is fine, but the ones that have kept their secrets well secret for over who knows how long, that is not cool. Sure everything turns out fine in the end, but it gives their enemies a name and a address book.  

Well i dont think it matters, if a hero is like tony stark, but it does matter to someone like batman. It just depends on the hero.

I think the heroes should always have an secret identity, not just for themselves but also their  
friends and families. 

The Fantastic Four had each other to protect themselves (English good) where as other Superheroes really do have to protect their families and friends.

If you look at there "enemies" they fight are very different.  Dr.Doom the mole people, and galactus arent really the same type of drug dealers, crime lords and general scum spiderman fights.  Ya there is rhino and sandman and of course Osborn, but look at what they do for their crimes.  Spiderman  deals with violent crimes like burglary, domestic violence( on occasion), and Gang wars. The FF intersteallar aliens, inter dimensional beings, and a crazy King. If doom ever orders a mob style hit, i quit comics.

Mmmmh, If I had super power, secret identity would be a must, because I would change the world in way that mattered (To me) and innocent people could get caught in crossfire, becoming collateral damage that I couldn't easily justify. 
 
More of that, maybe it's cool for the FF, but I wouldn't like to live near the Baxter Building : Between the experiment of Mister fantastic and the attack of their ennemies...hell, not a chance !

of course its entirely situational. 
The FF were borderline celebs before their accident, which everyone knew about. They were intelligent adults (mostly).  and they where also premier scientists, meaning they could more or less study themselves better than anyone else.
 Parker on the other hand was 16. if he had come out as a hero, he would have been a lab rat and possibly "property". And he went after low level thugs, the type who would break into  his house and do horrible things to his home and Aunt May. 
 
each situation is different. your origin and your villains. How your family would react and your sense of duity, and your powers. Those factors determine if you need a secret identity, and you really cant "decide" otherwise. Look what happened to parker. he decided he didnt need a secret identity, and now his marriage never existed.

I think a secret Identity is a must have for a superhero. The case of FF4 Vs. Spiderman the difference is Spiderman's villians are a bit more psychotic than the FF4's. I have never really been a fan of Spidey but he needs his secret identity more because his family and friends dont have powers to protect themselves like the FF4 do.

In my book, I wrote out secret identities for most of the characters. The main character can't even remotely look like she's human anymore so it's not like people are so stupid they would think there is ANOTHER tiger chick running around the city. The villains obviously don't give a crap being the selfish pricks they are, and the other heroes even if they DO look human have something that gives them away. So a it is a rarity in my book that people have secret identities.

if i had super powers i would do what the villains would do and try to make a lot of money off of it and in order for me to live a comfortable life i would have to have a secret identity to avoid the cops and other law enforcement agencies

Yes, I would have a secret identity. Otherwise I'd get the crap kicked out of me just by walking around in the middle of the day!

Certain characters need them and certain characters don't. I think for the most part characters like Spiderman, Dare Devil, and Batman they deal with a totally different brand of scum. Where as people like the Fantastic Four, Captain America, and Iron Man fight a higher class of villian. Doctor Doom, Kang, and the Mandarin are above such things as going after family. Its all in who you fight and Spidey and his type decided to go after scum bags without honor.
 
Although there are characters that have secret identities that don't really need them. Like for instance Superman, Lois already gets in enough trouble. I mean can she possibly get into any more.

i think it really depends on your powers and how famous you are , if you uber powerful or live with a collection of other heroes no real need since most things wont pose a significant threat , but if your uber famous solo hero i would say the identity would be useful.

If they don't need secret identities, then they don't need to wear masks. 

It really depends on the characters. The F4 are all superheroes. All of them have powers. And the series focuses on them primarily, with no other people unless they're interacting with fellow heroes. So with that, they have no one they care so dearly about that a villain would choose to strike against, save for each other.  
 
Spider-Man is different. Spider-Man has love interests. And while he does interact with other heroes like the F4, his stories are generally intwined with his personal life.  
 
Without a "Mary-Jane" or "Gwen Stacy" character, the F4 have nothing really that they would suffer from losing except from each other. And with their coordinated attacks and team-based style of offense and defense, they don't have much to worry about losing one of their own. Spider-Man always loves someone who is vulnerable, a normal human who could, oh say, be thrown from a bridge and have her neck snapped with his webbing (or was her neck already broken?), so he needs to protect those people. And to do so is to wear a mask.

Read Identity Crisis.

 This discussion is taking the "comic book hero" concept out of the comic book and trying to place it into the real world.     
So other than heroes whose lives are 100% controlled by a government, what hero is really just two dimensional and lives in a vacuum? Unless you're a sad example of humanity, devoid of personality and completely unable to relate to another person who simply shuts down or sits in a blank room doing literally nothing on his off hours, you have GOT to have friends, family (even distant relations) and those you care for and care for you. We aren't talking super villains here, we're talking super HEROES, those people with an extreme moral and ethical compass (likely coupled with an extreme sense of justic and compassion) that forces them to put their lives in mortal danger daily to protect others who THEY DON'T EVEN KNOW, and who cannot defend themselves! More than anyone else, heroes are people who will have relationships.
 I would say that the concept of prejudice (for alien, mutant or otherwise "different" heroes) is also a HUGE concern and another great reason to have a secret identity.
 
I think that the FF and Iron Man are both unrealistic examples in these terms for the very reason everyone else is stating that they CAN have their own identities. Anything that is CAPABLE of being a threat to them is CERTAINLY smart, clever or strong enough to threaten their friends, associates, and loved ones - otherwise these "heores" would be so powerful that NO THREAT would ever exist that would give them a challenge. 
If the FF is fighting galactic level threats, and is challenged by them, then those threats are very capable of affecting anyone who the FF cares about (even those with super powers of their own or someone like Alicia Masters). Otherwise the FF would have to be scanning the ENTIRE UNIVERSE and other DIMENSIONS all day everyday for threats and respond to them on a moment's notice giving those threats ABSOLUTELY NO TIME to wreak havoc. 

I site Thor. For decades Thor (who is a FREAKIN' GOD with OTHER GODS as allies) had a secret identity.....although I don't know what ever happened to that identity in the last 20 years since he became a lame militant Greenpeace/PETA eco-terrorist.

I agree, it depends on the hero, but honestly, a secret identity serves to protect the friends and family of the hero.   It's just a matter of the hero and his/her role in the public eye, if he or she is even in the public eye.   
 
Just to digress slightly, wtih Spidey, it's always bothered me that he doesn't try to hook up with a female super hero.  Why date a civy and have all the problems associated in this area?   
 
Maybe Parker wants to be "grounded" like Clark Kent, but honestly, I don't buy it.  I can see why he loved Gwen Stacy but MJ needs to get kicked to the curb....like I always say...because she's a slatternly woman.  Loyalty is NOT in her DNA, plus she whines all the time yet she's got one of the coolest BF/Husband (where do they stand now anyway?) in the world.   
 

I think it's a personal choice based on the hero. Some enjoy having another identity they can live through, if they were a superhero all the time I think it can get tiring. Even Batman turns into Bruce Wayne every now and again when he needs to drink Tonic Water at parties.

Wasn't the only reason Aunt May got hurt was because Peter left Stark Tower? Wouldn't have she been safer in Avengers HQ then some apartment?

Honestly -- so much of them are exposed right now -- there's no point of secret identities...

Spider-Man and the Fantastic Four have different types of villains.  In terms of real world criminals, Spider-Man's villains are akin to street gangs while The Fantastic Four's villains are more like the mafia.
 
While the mob may be hesitant to attack you at your home in favor of a much bigger plan, a street gang has no problem with driving by your home and shooting it up.  Spidey's villains are more grounded and dirtier, so to speak, and have no problems with those sort of attacks, while Reed and co tend to deal with people with grander feats in mind.

Secret identities make characters more interesting!!! it gives them a life and a second layer. even if its not secret, its so much less interesting to have a superhero who is ONLY a superhero. they need a second life at least! 
 
Superman without Clark Kent? boring. Spider-Man without Peter Parker? boring. 
 
it gives the characters a more human level. and it gives the character a cast! a group of supporting characters is just as important as having a main character. so Secret identities are a must. or at least a life outside the capes/costumes.

I think this depends on the character were talking about. Some characters, such as Iron Man or the Fantastic Four, are set up for a lifestyle where people knowing they are a hero is a benefit to them. But someone like Spider-Man on the other hand, needs his identity to protect those around him.

Yes its how we relate to them and how we connect with them.  They get to be who we dream could have the chance to be. 

I'm actually writing a novel series called Secret Identity. It's about about a group of friends and "frenemies" in San Diego between the ages of 17 and 24. The whole series revolves around how you don't know the character's last names. The reader gets to know their first names but that's it. I was inspired by the concept of Heroes, the secrecy from Animorphs, and the success of Harry Potter. I think secret identities work well. But in this case, all the heroes and villains know each other. They just stay secret from the government.

Yes of course to protect yourselves and loved ones

The FF have a support system. Most of their family, kids included, have powers. They don't have day jobs. They were celebrities from the start as well, so secret identities weren't really all that much of an issue. Besides, Ben's disguises aren't exactly convincing.
 

Well some hero's like Spiderman don't want they're family and friends to get hurt or anything by they're villains or people who are out to get that hero when they're not around to help them so that's basically why they wear masks.

This is one of the main reasons why I think iron man 2 is going to be a big successful drama of disasters. He gave his identity to the public at the end now the sequel is about the result of that. Because whiplash knows his target, Alcoholism is in effect with celebrity statues, and the military wants his stuff badly so iron man 2 will explain why most superheroes should hide there identities still. Iron man you dumb ass, now he must fight ongoing villains with high tech plus knowing him man I would be pissing in my pants if I was Stark.  

 
I Think it depends on the Hero... To People like Guy Gardener it's worthless, he has like no family or friends... but to people like Superman or Batman it's vitally important.

We all know the reasons why heroes have secret identities and the results that can happen from their identity (good or bad) becoming known to the general public or a member of their rogues' gallery. With that said though, I'm more interested in how many super powered individuals use their powers for their own benefits in addition or exclusively... I mean, everyone isn't gonna be broke like Peter Parker. 

Some might need it more as a necessity than others.

I would recommend it, if they have family, loved ones, and friends.

If you want a social life and friends and family your gonna need it unless you want to live a life like Tony Stark or The Fantastic Four constatnley attacked at home living in a house visited more than the white house no peace and quiet. Or you can be like Batman where the civilian is the mask and the Hero is the Identity

When secret identities become public, bad things happen (to the characters). Identity Crisis is a glorious shining example of the importance of the mask.