Heroes get a lot of leeway. The authorities understand that sometimes a crimefighter must rip up Midtown Manhattan to save New York. But some things are just palin illegal. The government takes a dim view of the following actions:

     Committing crimes: So-called heroes who rob banks, steal cars, kill, or endanger the lives of innocent people are no better than the villains they fight. Breaking the law in order to preserve it is rarely tolerated.

Withholding evidence: Equipment used in crime is evidence that must be turned over to the
      authorities. A hero who keeps weapons or equipment used in a crime is withholding evidence, in effect stealing from the state. Even destroying equipment reduces the state's chance to convict the criminal.

Vigilante action: Unless in law enforcement, a hero is just a private citizen. He or she can make a citizen's arrest and turn criminals over to the law. The hero cannot break the law in order to capture a crook, nor act as judge, jury and executioner. Any hero who takes the role of punisher is asking for big trouble from the law.