U.S. Internet companies are engaged in a two-front effort to defend the $100 billion they earn from online advertising. Companies such as Google and Facebook have been fighting proposed European Union privacy laws they say would slow innovation. Now, they are fighting in their backyard against California privacy bills that are almost identical, according to a recent analysis by Bloomberg Government’s top global business and technology analysts, Sanford Reback and Allan Holmes.

Among California’s more than two dozen privacy bills pending, one would require companies to tell customers who ask what personal information was shared with other companies and the contact information of the company the information was shared with.