I saw first hand a sales guy at a prior company I worked for start a side business directly competing with the primary business he was working for in his day job, while still working with them. Including redirecting customers while working for them.

The owner got suspicious due to some comments made by customers, and started listening in on the phone calls he was making on the company phone system.

This was a small business, and it nearly tanked the company, as the customers were confused as hell, and the ‘new’ company wasn’t doing well either. She ended up having to fire him, and sue him, but it took years, and meanwhile he kept operating.

He was paid well, but for some people it’s never enough.

I don’t care what anyone says, that is shitty criminal behavior.

That's basically the one situation in which non-competes are enforceable in the US. The problem is, most people don't understand that, and fall prey to companies putting non-compete clauses into their employment agreements that say they can't go do CRUD software development at any company in a 50 mile radius.

Yeah, I'd say that's different, not sure how the anecdote applies whatsoever.

The reason it’s relevant is because that is literally what a non compete is supposed to be for.

This is talking about non competes that apply after one is no longer employed.

Yours is something entirely different.

Different and yet his is a lot more valid than want most are

If it was different, then he would have been fine once he was fired no?

But that is not the case.

If he wants to quit and compete with you he should be able to even if this destroys your business. The problem is he used his access while employed to redirect customers. It wasn't fine after he was fired not because it wasn't ok for him to compete with his prior employer but because he had already swiped your customer base. The prior behavior and challenges after he left are inextricably intertwined. Him quitting didn't separate them.

If he had done NOTHING while employed and quit to do his own thing do you think it would have been a problem? If so why?

I think you might want to re-read things a bit.

1) It wasn't my business, and I'm not sure why you seem to think it was.

2) He only started the business because he was able to siphon off customers, and felt it was easy money.

3) If he had quit, and started his own business (even based on the prior one), and started from scratch, that wouldn't have been a problem. Him waiting a period of time (non-competes pretty much HAVE to be time limited to hold up anywhere) would not likely have changed it either.

But that would have required more work and more risk.

It's rare that folks actually do that.