Facebook on Friday suspended accounts for Strategic Communication Laboratories, the parent company of Cambridge Analytica, the data analytics firm used by Donald Trump’s presidential campaign ahead of the 2016 presidential election.

The suspension was issued because Cambridge Analytica received Facebook data from hundreds of thousands of users in a way that violated Facebook’s guidelines, the company said Friday in a blog post.

The backstory: In 2015, a third party app called “thisisyourdigitallife” used Facebook’s login API, which allows people to use their Facebook profile on third-party apps instead of creating a new account, to collect data on 270,000 people, which is allowed under Facebook’s rules and guidelines.

The app, which was run by a University of Cambridge professor named Dr. Aleksandr Kogan, then shared the data with Cambridge Analytica, which is against Facebook’s rules and guidelines.

Facebook found out about it, and demanded that both Kogan and Cambridge Analytica delete the data. They promised that the data had been deleted, but now Facebook says that “several days ago, we received reports that, contrary to the certifications we were given, not all data was deleted.”

Why this matters: Cambridge Analytica, which the Washington Post describes as “specializing in using online data to create voter personality profiles,” was used by the Trump campaign during his run to the White House in 2016. The firm has been under scrutiny from Special Counsel Robert Mueller, who is investigating Russian interference in the 2016 election. Back in December, Mueller requested that Cambridge Analytica pass along internal documents.

What this means for Facebook: The company says it’s still trying to get to the bottom of what happened. “Several days ago, we received reports that, contrary to the certifications we were given, not all data was deleted,” the company wrote in a blog post Friday. “We are moving aggressively to determine the accuracy of these claims. If true, this is another unacceptable violation of trust and the commitments they made.”

Regardless, it puts Facebook in another awkward position as the company continues to try and determine what role it might have played in helping Trump get elected. We’ve already learned that Russian sources used Facebook to spread disinformation to millions of users, and even bought ads intended to create divisions between American voters. Now we’ve learned that Facebook data that was easily and appropriately collected under the company’s policies may have been unknowingly used to help Trump’s advertising campaigns.

What we still don’t know is whether this data was used by the Trump campaign or, if it was, what impact it might have had. While 270,000 people sounds like a lot, it’s a very small portion of Facebook’s user base, and would represent a very small portion of the potential U.S. electorate.

It’s also unclear if Cambridge Analytica is still working with the Trump White House or is helping with his re-election campaign. Or what Cambridge Analytica could do to be un-suspended from Facebook, or what Facebook would need to find in order to ban them entirely.

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