Could there be an impact from putting up some billboards about the legality of certain actions, where police officers would be likely to see them frequently?
I doubt it. There's too many ways for this not to work - the police testifies "I never saw that billboard". Even if they admit they saw it, so what? Anybody can say anything on a billboard, the police officer could say "Oh yeah, I saw it, but I have no idea if it's true" - and plausible deniability is sufficient as I understand it.
"Oh yeah, I saw [the satirical facebook page about us], but I have no idea if its true"
It's infuriating that this farce is what our legal system hinges on.
You can even put it on their qualification tests so you have documentation that they heard something was illegal and it doesn't matter. For many things they are effectively immune to prosecution. Add on that most prosecutors don't want to go after cops because they won't cooperate in cases after that.
Yea police are definitely known to absolutely never ever testilie.
Probably not. You can tell a police officer something is illegal, I'm not sure why they'd be inclined to believe you, especially in the context of you being arrested.
Interesting idea. Although the cops might claim they did not believe the billboards were accurate.