Who Owns The Federal Reserve?
The relevant page is here: http://www.boe.ca.gov/lawguides/business/current/btlg/vol1/sutr/1654.html
Eventually, the state of California will do what it has done for virtually every barter exchange system that has ever come down the pike and start auditing those who have accepted bitcoin to see if they collected the sales taxes. And when it turns out that they didn't (which most have not), the state will start the cascade of fines and assessments as well as suspensions of resale permits.
Google is well aware of these issues, they've been through that disaster in the early stages of their company, and will not get into the cryptocurrency game without drastic changes in the law.