Not under California law (Score 4, Informative)

One of the reasons that California's tech sector is dominant, and that California has such a history of innovation, is that California law does not enforce non-compete contracts except in very narrow circumstances. IAAL, and as someone who has litigated these cases before, I suggest to any employee that they attempt to negotiate a California choice of law clause in their employment contracts, especially if they work in California or for a company based in California.