Batman is a highly skilled crime fighter. He has spent his life training and honing his mind and body. He faces incredible and deadly villains everyday. His costume offers minimal protection against his deadly foes and the threat of gunfire from low level street thugs.
Besides his hand-to-hand fighting skills, Batman has an arsenal of Bat-gadgets at his disposal. Up until recently, Batman had to figure out how to manufacture and pay for all his weapons and tools. Being a billionaire doesn't hide the fact that he is still responsible for file taxes and explaining to the board of directors at Wayne Enterprise where all the money goes.
One of Batman's most valuable gadgets has been the Batarang. This simple device has saved his life on countless occasions. Able to throw them with expert precission, the Batarang can be used to easily disarmed the cowardly thugs brandishing firearms. It can also be used to knock out or disable crooks as they try to flee from a crime scene. There has also been occasions where Batman has used a Batarang to free himself from a villains insane but deadly trap.
With all the Batarangs Batman has used and thrown around over the years, what happens to all the discarded ones? Is it safe for Batman to simply leave them lying around the streets of Gotham City?== TEASER ==
Batarangs most likely aren't cheap to make. It's possible Batman is able to have them mass produced somehow but it's not something that can be made without careful attention to detail. Batman needs to know the balance and design of each one in order to affectively throw them at his target. I don't think he would have the time to test out each individual one before hitting the streets. That's time being taken away from apprehending criminals and saving innocent lives. Cost might not be a big factor for Batman, especially now that Bruce Wayne has publicly announced he is funding Batman's crusade against evil. It still seems like a waste of money to just leave them lying around.
Before the world knew about Wayne Enterprises providing tech and gadgets for Batman, he would have to be careful not to leave any incriminating evidence behind. As the world's greatest detective, he knows the slightest clue is enough to reveal the truth. Batman would have to be sure he never handled a Batarang without gloves. They can't be any traces of fingerprints or DNA from him or whomever manufactures them. This is just another reason he shouldn't leave them in the streets.
Even though Batman is against brutally disabling his opponents, the Batarang could easily be used as a deadly weapon. Seeing how they are able to be thrown and lodged into a brick wall, you can imagine what they would do if thrown at a person's chest. The tips or edges could also be used to slice a person's throat. How easy would it be for someone to commit murder and use a found Batarang in order to try to frame Batman? This is something that has happened to Spider-Man when some rogue police officers left discarded Spider-Tracers at the scene of crimes.
With Batman's brilliant and calculating mind, keeping track of where and when he threw each Batarang would not be a problem. But again, his time would be better spent solving crimes or capturing escaped villains rather than return to where he had a showdown and retrieve any thrown Batarangs.
In the old days, he could have sent Robin out to get them. Unfortunately for Batman, the roll of Robin now commands more respect. Maybe he could offer some sort of bounty on any recovered Batarang. I recall being told that supermarkets used to pay people if they returned any found shopping carts that were removed from their parking lots. I doubt this is the case today but Batman could try to do something similar. He could try to find a team of needy individuals or even homeless folk to go around and gather them. He could pay them $10 bucks for each one they find (or more since he's loaded and the cost of a new one is most likely more).
Whatever the case, Batman is being irresponsible if he's just leaving them lying around. You could think of it as litter or, more realistically, deadly weapons being left behind. Besides the criminal element that could find them, there's also the possibility that children could find them. Couldn't you just imagine kids playing Batman and accidentally throwing one and harming someone? If Batman doesn't already have a plan to recover all his discarded Batarangs, he really owes it to the people of Gotham City to keep his toys where they belong.