They aren't always legal - or rather they rarely hold up in the court of law. (USA at least) What I've been told by my lawyer is basically the only time it wil

They aren't always legal - or rather they rarely hold up in the court of law. (USA at least) What I've been told by my lawyer is basically the only time it will hold up is if you can prove that it was violated and your company was significantly harmed as a result (ex: You took 50 clients with you to the new firm). And the time period was reasonable (ex: 5+ year non-competes are likely never held up as the time period is absolutely unreasonable in almost all cases) Additionally, it has to be worth it to the company to actually go after the person who violated the agreement - it is civil not criminal. Which in the end results in a system where they are hardly ever enforced if violated and serve more to scare people from violating them then actually being legally enforceable.