My first job out of college was at a startup that focused on financial regulatory compliance.. I had no CS degree, barely knew how to program, and was generally a mediocre employee. I quit after five months and went to a company that offered a competing product (although I wasn't going to be working on it). The original company tried to sue me for violating my non-compete, and I almost lost that new job. Fortunately the new company negotiated on my behalf and I was transferred to a different company under the same corporate entity to wait out my non-compete.

This stuff happens, unfortunately.

The issue is that an extremely sensitive negotiation (interviewing and hiring process) is utterly disrupted by their presence, so nobody is in a good position to legally challenge them. If almost ANY non compete is in place, the potential employer is highly likely to make the decision not to bother with the candidate. Proving that it was because of the noncompete is difficult (making it difficult to prove real damages).

They would almost certainly fall apart in court, but the systems they disrupt don’t survive long enough to move them into court.

It's not that they'd fall apart, it's the fact that you have to retain a lawyer to get a new job. Sure, you'll win eventually, but at what cost?

I've seen that stunt go to the point of pressuring a startup into a buyout. You need a lot of money and confidence to rely on courts.

Perhaps you are thinking of California? This is certainly true in California, but I've seen non-competes enforced in the tech sector elsewhere in the US (Seattle, Utah, etc).

California law goes as far as to state you can't have a non-compete agreement in the work contract at all. When I worked in Seattle, my contract had a non-compete that specifically said it didn't apply in California, and then the fucking staffing agency tried to tell me it wasn't a non-compete.

I called Bullshit! It explicitly excludes your California office! Don't try to lie to me!

I am in exactly this situation working in Seattle for a Cali company.

I lost a job due to one. This was in NY. I had signed the offer and the new company's counsel withdrew the offer because of my current employer.

interested, how did they find out?

I provided my employment agreement to the new company when they asked for it.

Probably put his previous job on his resume or they looked up his previous job using a credit reporting bureau

Often it's just that the two companies are aware of each other's policies. If they've heard of Company B and know it has a non-compete they just reject you.

Kind of weakens the argument for negotiating the non-compete clause(s) out of the contract. You might get screwed anyway if the hiring company assumes you had to sign one.