A bipartisan group of senators on Thursday unveiled legislation aimed at forcing tech giants and social-media companies to disclose the individuals and entities who buy advertisements on their platforms. Under the legislation—introduced by Sens. Mark Warner (D-CA), Amy Klobuchar (D-MN) and John McCain (R-AZ)—the threshold for disclosure would be $500 in ad buys on platforms such as Facebook and Google. The initial threshold when the bill was first discussed was $10,000. “While TV and radio ads have to be filed... that is not true for online advertisements,” Klobuchar said at a press conference. “If a candidate or cause buys an ad for TV, the same rules should apply if they put it on Facebook.” The bill represents the first legislative effort in response to Russia’s meddling in the 2016 election.