Last week, the Federal Election Commission took a rare unanimous vote to begin drafting regulations that would require greater transparency in online political advertising. The motion is a welcome sign of life from a group long paralyzed by partisanship. And it’s a reminder that Russia’s use of online ads to meddle in the 2016 presidential election should be a matter of concern across political parties.

It’s not yet clear how much influence Kremlin-funded advertisements had in shaping the 2016 election. But a full accounting of Russian interference requires that technology companies and the government both take a hard look at how those ads were allowed to run unnoticed. Facebook, for example, has found 470 fake Russian accounts and pages that ran about 3,000 ads for a total cost of roughly $100,000. Some ads pushed political messages tied to one presidential candidate or the other, while others magnified divisive social issues such as gun rights or immigration. Facebook users had no way of knowing who had funded the ads — and because Facebook allows advertisers to target paid posts to specific cross sections of the population, many researchers and news organizations had no idea that the ads existed at all.

Facebook and Twitter have both pledged to increase the transparency of advertisements on their platforms, providing users with more information about which posts are ads and who’s behind the funding. But as both companies seem to recognize, self-regulation isn’t enough.

The FEC currently requires that political advertisements supporting a particular candidate include a disclaimer of the ad’s funding. Yet companies such as Facebook and Google have pushed to exempt ads on their platforms from the requirement: They argued that, like bumper stickers, which the FEC also exempts, the ads were just too small for the words to fit. In 2010, the FEC allowed Google ads to link to disclaimers rather than include them. In 2011, Facebook argued that its ads shouldn’t even have to include a link. When the FEC was unable to reach agreement one way or the other on Facebook’s case, the company chose to allow ads without any disclaimers or links.

In the wake of the Kremlin’s meddling, the big technology companies are now cautiously supportive of the FEC’s opening the door to further regulation. To be sure, one rule won’t solve everything. The disclaimer requirement applies only to advertisements funded by a political committee or endorsing a particular candidate — so Russian ads stirring up anger over Black Lives Matter, say, would have been exempt anyway. For that reason, Congress also has a role to play in crafting a legislative solution. Sens. Mark Warner, D-Va., and Amy Klobuchar, D-Minn., have introduced a bill to apply the same disclosure requirements used for television and radio ads to Internet ads as well.

Having broken its deadlock, the FEC should now close this loophole and craft a rule requiring some form of disclaimer for online advertisements. The committee’s vote is just one step, but it’s an important marker of progress toward increased transparency for political ads online.

Editorial by The Washington Post