I was reading an article and fell upon this link.

Apparently in Montana, it's illegal to do anything about a police officer who is actively violating the law, as long as the officer is in uniform.

So apparently if you're in Montana and you come across a police officer who is in uniform and is beating a 4 year old into a coma with a night stick, it's illegal for you to do anything about it...

This would never happen you say? Okay, how about a more realistic example (which apparently has at least occured once). If a police officer wants to search your home, but doesn't have a warrant or justified cause, telling him he cannot search your home is a direct violation of this law. It's an illegal search, but he is in uniform and performing on duty, so it's a crime to not give him permission (because you would be interfering with his illegal request)...

Nice...