"Who wins often depends upon a race to the courthouse. For multi-state employers it is often a rush to the courthouse to determine if a non-compete agreement is valid. The employer's strategy is to get an order outside of California in their favor. The employee or California prospective employer's strategy is to get an order within California in their favor. In the face of dueling, and opposing orders, the first to the courthouse may win because states often must give effect to orders from other courts."
The whole thing is actually very interesting, worth a read.
As most other authorities describe in greater detail--it doesn't matter who wins the race to the courthouse. The non-compete will be valid in whatever state was selected as choice-of-law, but the non-compete provisions will be invalid in California because California generally prohibits non-competes except in very limited circumstances (such as owners of the company).
Consequently, a non-California non-compete is not valid within the state of California, even if another state's court validates it. This means that so long as the employee remains within California, the non-compete cannot bar them from seeking further employment in California, even if it would otherwise violate the non-compete. However, by the same token, even if a California court invalidates a non-compete, it only applies within California--the non-compete may remain invalid in other states (depending on their laws regarding non-competes) if the employee were to attempt to seek employment outside of California during the term of the non-compete.
I had heard similar - that if you go to CA, you have to pre-emptively sue to get out of it.
Are non-competes enforced often enough that this is an issue?
I've only heard of a few cases, and these were notorious hedge funds, or flagrant post-move poaching of employees. (Not just "I'm gone" but "I'm gone and taking my team even though I signed something that said I wouldn't.")
I read a very interesting thing about how non-compete agreements signed in other states are treated in California...
http://lawzilla.com/content/noncompete.shtml
"Who wins often depends upon a race to the courthouse. For multi-state employers it is often a rush to the courthouse to determine if a non-compete agreement is valid. The employer's strategy is to get an order outside of California in their favor. The employee or California prospective employer's strategy is to get an order within California in their favor. In the face of dueling, and opposing orders, the first to the courthouse may win because states often must give effect to orders from other courts."
The whole thing is actually very interesting, worth a read.