Mark Zuckerberg announced Facebook would make political ads more transparent. Facebook You probably saw it dozens, if not hundreds of times in the months leading up to the US presidential election last year.

A political ad would air. And at the end, you'd see a clear message about who paid for or endorsed the spot, whether it was Donald Trump, Hillary Clinton or any of the numerous candidates or political action committees.

Such messages have been the standard in political advertising since 2002, when Congress passed a campaign reform law that required them. Now, whenever a political message runs on television or in any other traditional mass media, you can see who paid for the ad. I think we can all agree that kind of transparency is a good thing.

However, that disclosure requirement doesn't apply to online ads. As a result, when you see a political ad on Facebook or Google or other sites, it can be impossible to tell who was behind it, whether it was a particular candidate, a PAC, a non-profit — or a fake account run by groups linked to Russia.

You just don't know.

But you should. Facebook, Google and the other giant online services have become hugely influential when it comes to spreading news, information and advertising. As such, they should be held to similar standards as other forms of media when it comes to political advertising.

Facebook is a case in point for why such standards are needed. As it turns out, there were plenty of ads placed by fake Russia-linked accounts during the 2016 election cycle. There's reason to believe those ads were part of a propaganda effort intended to influence voters without them understanding who was behind it.

Facebook disclosed earlier this month that it discovered about 3,000 such ads, and last week it turned them over to the congressional committees investigating Russia's alleged attempts to meddle with the election.

Belatedly Facebook itself has recognized the danger. Company CEO Mark Zuckerberg, who initially dismissed the idea that anyone tried to surreptitiously use his company's social network to influence the election through fake news or ads, is now singing a different tune. In the wake of the latest disclosures, he promised to require more transparency for political ads placed on Facebook.

Going forward, political ads will have to show the Facebook pages that paid for them. And Facebook users will be able to see what messages advertisers are targeting at particular audiences on the social network, he wrote in an open letter.

"I care deeply about the democratic process and protecting its integrity," Zuckerberg said in a video message broadcast through his Facebook page. "I don’t want anyone to use our tools to undermine our democracy."

Those are good first steps, but they don't go far enough.

It's unclear, even with these steps, whether users will be able to know the actual individuals or companies — rather than the Facebook pages — that are funding particular ads on the social network. It's also unclear what Facebook will do ensure that the accounts behind those ads are legitimate.

Much of the advertising on Facebook is set up through a self-service online tool. That feature seems ripe for abuse.

Just last week, for example, Pro Publica discovered it was possible for someone using Facebook's automated ad tool to buy ads targeting "Jew haters" and other nasty groups. Facebook removed those categories, and blamed its algorithm for making them available in the first place. But the company hasn't given a clear picture of how it'll keep people using fake accounts from abusing that tool in the future.

And the problem with online political ads is much bigger than Facebook.

On Thursday, Twitter said it found 201 fake accounts linked to the same Russian actors who set up fake accounts on Facebook. But that is likely just a small fraction of the abuse on that platform. Sen. Mark Warner blasted the company for basing its disclosure purely on the same accounts linked to the ones Facebook found, saying it "either shows an unwillingness to take this threat seriously or a complete lack of a fulsome effort."

And we haven't even heard from Google yet.

Even if such companies were earnestly trying to contend with the problem posed by online political ads, there's reason to doubt their ability to solve it on their own. These, after all, are the same companies that have struggled to contend with other ways people have abused their services, from using them to send spam to live-streaming murders over them.

That's why it's time for governments to step in — and for the big online service providers to work with them constructively. The best thing Facebook, YouTube, Instagram, Twitter and the like could do is to work with the Federal Election Commission and Congress to come up with a standard for online political advertising just like we have for television, radio, and print.

"All of these tech firms would benefit from a clear set of guidelines from the FEC or governments around the world," said Daniel Kreiss, a professor of political communication at the University of North Carolina's School of Media and Journalism. "On one hand we can say Facebook has too much power. On the other hand, I don't think they're well equipped to do that. This is why governments should set guidelines."

Sen. Mark Warner is working with Sen. Amy Klobuchar to set new disclosure rules for online political ads. Joe Raedle/Getty Images Congress has neglected the issue of online political ads for years, but it finally looks like it may rise to the challenge, thanks to the Russian influence investigation.

Senators Mark Warner and Amy Klobuchar are working on a bill that would require internet companies with 1 million or more users to keep a public record of political ads purchased on their services, according to CNN. Those companies would have to disclose information on political advertisers spending $10,000 or more on political ads.

For reference, Facebook said the fake Russian accounts bought about $100,000 worth of ads through the company's automated advertising tools.

But even Warner and Klobuchar's legislation likely won't be enough to address the problem.

The advantage of advertising online is that it provides more bang for the buck than traditional advertising. Even a small ad spend can have a big impact. So setting the limit for disclosure at $10,000 of ad spending may be placing the bar way too high. Kreiss, for one, argues it should be far lower.

And political advertising is only one of many areas on these online services that's prone to abuse and could be used to manipulate the political process. There's also trolling, fake news, bots, and more.

But the legislation is a move in the right direction. It recognizes that online political advertising is one aspect of the abuse and manipulation problem that can be addressed relatively easily. We already have a model for how to do it in the form of the standards applied to other media.

Here's hoping Congress passes the legislation or something like it. Facebook and other online services are no longer niche websites used by the few. They're the sources of news and information for billions. Their reach and influence is arguably larger than television. At the very least, they should be held to the same standards as other forms of mass media.