Silicon Valley does not have rent control...it aint NYC
What's happened is that the young techies are living in the urban areas - San Francisco and Oakland, and commuting in company sponsored buses to the Silicon Valley.
San Francisco does have rent control. I don't know if Oakland does.
Here is an old Cato study that shows San Francisco and San Jose both having very bad rent control. I don’t know how bad it is now. But rent control probably hurt the Bay area market for a long time. But the big issue making prices high in the region now is probably Silicon Valley prosperity. Better that then Baltimore economic depression!
http://object.cato.org/sites/cato.org/files/pubs/pdf/pa274.pdf