So, what does this mean? Close to 80% of all FCC actions are postal -a letter saying: cut it out- or visits (call them warnings). Only 1.5% had an arrest or conviction associated with then. And an arrest isn't a conviction. I'm better the actual 'conviction' rate is less than 1%.
So, the reality is: being a radio pirate is relatively low risk if you don't let the 'warnings' actually scare you out of taking back your airwaves.