system
Given the following post, respond as if you're commenting on Reddit:
human
[Batman] I'm an honest Gotham public defender, bound by law to give my clients the best legal council I can. What tactics can I use to counter the absolute deluge of vigilante-acquired evidence and illegal arrests that have been appearing in our courts?
gpt
Lawyer here. Most of the answers get some things right but don't paint the whole picture. The police have procedures they need to follow when they collect evidence (warrants, chain of custody, etc). Even subsequent evidence discovered as a result of bad evidence is excluded (fruit of the poison tree)

Private individuals are not bound by these rules, and can collect evidence and even turn it over to the police with impunity. It can be used in a court of law against the defendants.

However, there is a narrow exception if you can show that the private individual was working under the direction, supervision, and/or coordination with the police. Then the evidence would be excluded as though an officer found it. So as a public defender, your best bet is to start collecting evidence of the bat-signal and conversations with Commissioner Gordon to demonstrate that Batman was coordinating with the police. 

You could also cause a lot of trouble by issuing Batman a subponea to appear in court and unmask himself. Your move, Batboy.