These revelations reinforce the need for effective regulation of digital political advertising. The Federal Election Commission should repeal its exemption for disclosures on small online political ads, and Congress should pass the Honest Ads Act. Furthermore, Congress should expand that bill to include additional protections for the American public against the varied activities of disinformation agents.

Despite the recent criminal indictment, and Special Counsel Robert Mueller’s investigation into possible collusion between President Donald Trump’s campaign and the Russian government, Americans continue to lack an accurate picture of the aggregate impact of foreign disinformation campaigns on U.S. elections. We have very little knowledge of what actual content the Russian disinformation operators pushed onto popular Internet platforms; how much money they have spent on their propaganda campaigns; which classes of the U.S. voting population were targeted by their campaigns; and which Americans actually saw their misleading content.

The FEC has the authority to take the first step in instituting transparency in online political advertising. In 2014—when the commission may not have fully appreciated the impact of digital ads on American elections—it decided that web-based political ads are typically too small to allow in-ad disclosures about their sponsorship; such disclosures are required for political ads on broadcast television or radio. However, given what we now know about the deleterious effects of misleading digital ads on national politics—as evidenced in the 2016 election cycle—the commission should repeal its 2014 exemption and require disclosure of the provenance of all digital political ads within the ads themselves.

In March, the FEC issued two proposals explaining how political advertisers running small digital ads on mobile apps and Internet platforms could reasonably include short-form disclosures about the sponsorship for these ads. Although the commission held hearings on those proposals this summer, it seems unlikely to adopt them in the near future due to gridlock between Democratic and Republican commissioners.

Should the FEC fail to act promptly, Congress should pass the Honest Ads Act introduced by senators Mark Warner, Amy Klobuchar, and the late John McCain in the wake of the 2016 elections. This bill would effectively apply the same disclosure requirements on political advertising for broadcast television and radio to all digital forms of political ads. This bill would also require major digital platforms to maintain public databases disclosing the identities of large advertisers that actively push political content on the platforms.

But Congress should go further by establishing parity in practice between the regulation of political ads on digital platforms and those on broadcast television and radio. In other words, voters should know not only that a digital ad is political and who is sponsoring it, but also its target audience and actual viewership. The public can ascertain these metrics for any broadcast ad—because we can monitor which networks are playing it and estimate how many people are watching it in real time. But the public cannot determine these metrics for any digital ad because hosting platforms keep secret the statistics on their target audiences and user engagement.

Only with this added transparency—showing the potential and actual impact of digital political ads—will we achieve effective parity with political ads disseminated over broadcast and radio networks. When Americans are shown a political ad online, they should know why they were targeted by the advertiser, how much the sponsor paid to push the ad, and who else might be seeing that same ad. Without this fulsome transparency, online political ads will continue to be presented in a misleading manner by misinformation agents—including the Russians.

Regrettably, the leading Internet platforms have pushed back against the Honest Ads Act with tremendous vehemence. Although Facebook executives did—in the immediate aftermath of the Cambridge Analytica scandal—publicly state that they would consider any legislative proposals to regulate political ads on the Internet, they have since favored their own voluntary actions as symbolic tokens of reforms, such as Facebook’s introduction of its Issue Ads policy.

But voluntary actions are not a sufficient replacement for laws in this area. First, not all Internet platforms are likely to agree to a common set of reforms. Second, none of the platforms are likely to agree voluntarily to the expanded set of reforms suggested above. Third, neither private citizens nor the U.S. government could take legal actions to force the digital platforms to abide by their voluntary commitments and punish failures to do so.

If we have learned anything from recent national election cycle, it is that we cannot trust the large digital platforms to voluntarily act in the public’s interest. If Americans want to know what digital advertising tactics are being employed by foreign agents to influence U.S. elections, the FEC and Congress need to adopt binding transparency laws—as soon as possible.

Dipayan Ghosh is a fellow at the Shorenstein Center at the Harvard Kennedy School. He previously served as a technology and economic policy adviser in the Obama White House, and as a privacy and public policy adviser at Facebook. Robert C. Pozen is a senior lecturer at the MIT Sloan School of Management, and a senior non-resident fellow of the Brookings Institution.