As a young corporate go getter, I signed a few non-compete contracts. In two cases, I was lured away by a competitor. In both cases, I tried (unsuccessfully) to hide where I was going. My old companies found out and tried to enforce the non-compete as punishment.
Both times, my attorney filed the necessary paperwork, we showed up in the first case and my boss was threatening me outside in the lobby before we went in, telling me I'll never work in this city again. We go in and judge basically laughed at the company and tossed the case immediately.
I don't remember the slew of cases he listed, but the message was clear. You cannot keep someone from working in their chosen field simply because you don't like your competitor. Since no laws were broken and I left with literally nothing but the suit I wore in on my first day - they didn't have any reason to keep me from working in my field.
The other case went the same way a five or six years later.