The web is getting clogged by news sites claiming to be local news sites, but the reality is quite different. Fake stories are getting shared on social media by unsuspecting readers, with national news sites writing coverage about the "local" news. And the misinformation is causing big problems.

It’s easy to see how mistakes could happen because of the nature of the internet. There’s no explanation, context, or credible website to back up a story before it’s shared. And that’s why we found that two fake local news sites, complete with real-life media sponsors and fake TV news anchors, had been around for at least five years.

We studied 100 fake local news websites across six major media categories, including news and radio. Some reported huge circulation and huge names behind their stories. But their reporters and editors weren’t well-informed, and the fake site’s sites had locations — including Sioux Falls, South Dakota, and Plymouth, Michigan — that were off-key and not recognizable in any photo.

We also analyzed data from ads served from 117 advertisers. Using a technical examination, we learned that in 2018, ads from 11 advertisers bought ads on the two fake local news sites, both based in Florida. One network sold nearly 80 percent of ads, and the other sold about 10 percent. The ads didn’t match the advertiser’s website.

We looked at the major news companies that partnered with the website, warning them about fake local news. None immediately responded to our requests for comment.

You should question any news story that contains some unsubstantiated statement or insinuation, but stories that repeat some variation of a topic can be more telling. Google News Lens, an experimental feature of Google News that identifies foreign news stories and photos, did spot mistakes in The Washington Post's fake local news stories and told them, so that might be a good way to look at the spread of misinformation online.

To read the full story and see this list of fake local news sites, head to BuzzFeed.