I assume it's not that easy to prove, so most people don't take legal action. Personally, I don't take legal action even if I think I can win the case, because

I assume it's not that easy to prove, so most people don't take legal action. Personally, I don't take legal action even if I think I can win the case, because it's just too much time and effort, and I don't want my life to focus on said legal procedure for the next n months. I assume other people also think they need to choose their battles.