Add this to the list of Facebook changes: the social network has formed a political-action committee. The “FB PAC” will now allow employees to donate to candidates in future elections. The group was officially incorporated on Monday, though it’s unclear which races will benefit immediately. The decision is part of a growing trend of Web companies getting involved with Washington. In the second quarter of this year, Google spent more than $2 million on lobbyists, and Facebook spent $320,000—both increases from the first quarter.