The rumblings of a defection—a potentially serious blow to one of Washington’s most powerful lobbies — come weeks after Yahoo left the Chamber in October, largely over its support of Sen. Patrick Leahy’s (D-Vt.) online piracy bill, the PROTECT IP Act. A source close to Google said the company is “frustrated” about paying dues to an organization promoting legislation that would “impose new liabilities” on Google. A second source close to the company confirmed that thinking. The Consumer Electronics Association, one of the country’s largest trade groups, is also weighing whether to part ways with the Chamber over its aggressive campaign for the Senate bill and its companion introduced in the House last week, the Stop Online Piracy Act, a tech industry source said.

Google and a powerful trade association might join with other hi-tech giants, and leave the U.S. Chamber of Commerce

That makes it Yahoo, as well as Apple and a handful of others who've either quit outright, left the board, or denounced the Chamber for it's political activities. Additionally, local Chambers continue to leave the national organization.