Our justice system is far from perfect, but it's better to have due process and transparency than to have corporations or mobs selectively enforcing "the law" however and whenever they see fit.

There's no reason to think that just because police exist people can't do anything about other people's bad behavior though. For example, when someone says something you don't like you aren't allowed to silence them because that violates their rights, but you are allowed to use your own rights to speak out against them and what they've been saying.

Crimes should be dealt with by our legal systems, but there are plenty of other ways to deal with things that simply offend us.