Google and Facebook are looking to make an early imprint on legislation being drafted in the House and Senate that would force them and other online networks to disclose information about the buyers of political ads. Lobbyists from the Silicon Valley behemoths have met with the staffs of Sens. Mark Warner and Amy Klobuchar and Rep. Derek Kilmer, all of whom are drawing up bills that would impose new regulations on the industry, according to Democratic aides and company representatives. The Senate bill is expected to be formally introduced next week. It is not clear when the House legislation, which has not been previously reported, will be introduced. Facebook has talked with those working on the bill, a company source confirmed, characterizing Facebook as willing to continue discussing it as the process moves along. A spokesperson for Google declined to comment.