Voters, especially in swing states, are used to being bombarded by political TV ads in election years, or receiving hundreds of direct mail ads that go straight in the trash. One place they might not be so used to seeing them is on their snackable and shareable digital media sites, like BuzzFeed. In 2016, nestled between posts ranging from “Split Supreme Court Means A Win For Public Sector Unions” to “18 Things You’ll Understand If You’re Obsessed With Hot Cheetos,” you might see a paid political ad.

Earlier this month, The American Prospect’s Justin Miller noticed a BuzzFeed post by Our Principles PAC, an anti-Trump super PAC founded by former Mitt Romney staffer Katie Packer. The post is labeled “Political ad” and featured a disclaimer that the post was paid for by the PAC. It contains GIFs of a TV ad produced by Our Principles, showing women reading out sexist statements made by Donald Trump. BuzzFeed Partners posted it on Facebook and it was shared more than 1,400 times.

This isn’t the only post like this at BuzzFeed. In January, Bernie Sanders’ campaign ran an ad on BuzzFeed, “15 Reasons Bernie Sanders Is The Candidate We’ve Been Waiting For,” featuring a mix of embedded tweets, videos and memes of Sanders quotes. It also included a section where readers could sign up with the campaign by entering their name, email and zipcode — vital data that campaigns work very hard to collect.

These posts aren’t the same as BuzzFeed Community posts from political or advocacy organizations that you may have seen, like this post about the Affordable Care Act by The Heritage Foundation, replete with amusing GIFs. In those cases, the organization makes the content themselves and posts it to the site just as any other BuzzFeed Community user would. But the native ads are different, and not just because they’re paid. BuzzFeed’s in-house team will create content for advertisers, including political organizations — in this case, taking Our Principles’ ad and turning it into the GIFs in the post — as part of their fee. They’re called “native” ads because they’re designed to look mostly like regular posts on the site, though with disclaimers; outlets from Mic to The New York Times run native ads too, and many outlets have an in-house creative team to produce them like BuzzFeed does. Likewise, BuzzFeed is not the only outlet that provides these paid native ads for political campaigns: POLITICO ran a paid op-ed opposing for-profit prisons by Bernie Sanders in February.

The ethical issues around native ads, particularly political ads, have been extensively covered and agonized over by media reporters — Poynter published a good rundown of the issues when BuzzFeed first announced it would be doing native political ads and videos last year. And it’s important to note that readers can have trouble distinguishing between paid ads and regular content. (Similarly, we should clarify that the in-house creative team that creates these political ads at BuzzFeed is totally separate from their reporters who cover those politicians.) But another problem with political native ads — one that receives less attention — is the lax disclosure requirements.

Take the Our Principles ad on BuzzFeed that ran on March 14. Looking at Our Principles’ independent expenditure reports from around that date, there are several that could be for the BuzzFeed ad — a $10,000 payment to DDC Advocacy on March 14 for “Online advertising,” or several payments of hundreds of thousand dollars on March 12 for “Media placement” to a company called Medium Buying, LLC. (It’s been reported elsewhere that BuzzFeed native ads can cost up to $100,000.) But it’s impossible to tell because no one is required to list anything about the value of the contract.

We’ve written before about the “Internet blind spot” — the fact that disclosure of paid political ads online is far behind disclosure for TV and radio ads. When a campaign runs a TV ad, the station must post the contract showing who placed the ad, how often it ran, and how much it cost; no such rules exist for Internet ads. The only way to see them is in FEC filings, and that can be a dead end too. For example, the ad placed at BuzzFeed or POLITICO by the Sanders campaign wouldn’t show up in FEC filings because their digital ads are bought by Revolution Messaging, and most campaigns do their media buys through agencies like that. On the FEC filings, the expense will show up as a lump sum — giving us no idea about the exact amount spent on these efforts.

Sites like BuzzFeed aren’t breaking any rules when they put these ads up, and campaigns are complying with requirements when they just list the purpose of these expenses as something vague like “Media placement.” But this process doesn’t leave voters very informed about these ads. Voters deserve to know who’s behind the political ads they see, how much they cost and how often they run, no matter where they’re placed. With a growing focus on native ads, there’s a whole new frontier in opaque political spending.