Sen. Elizabeth Warren is putting a spotlight on Facebook’s ad policies by turning the tables on the powerful social network. Following a week in which Facebook has been extensively criticized for its policy that allows politicians to lie in paid advertisements, Warren decided to place an ad of her own that makes false statements about Facebook and its chief executive, Mark Zuckerberg.

“Breaking news: Mark Zuckerberg and Facebook just endorsed Donald Trump for re-election,” the ad reads. “You’re probably shocked, and you might be thinking, ‘how could this possibly be true?’ Well, it’s not. (Sorry.)” The ad then goes on to state that Zuckerberg has “given Donald Trump free rein to lie on his platform.” Although television networks usually reject ads with blatant falsehoods, “Facebook just cashes Trump’s checks.” The presidential hopeful then goes on to say that Facebook “already helped elect Donald Trump once” and is now “deliberately allowing a candidate to intentionally lie to the American people. It’s time to hold Mark Zuckerberg accountable.”

Elizabeth Warren is running this completely false ad against Facebook and Zuckerberg to challenge Facebook’s unwillingness to block misleading ads.

HT @juliacarriew pic.twitter.com/wGrWwVWc53 — Siva Vaidhyanathan🗽🤘🏽 (@sivavaid) October 11, 2019

Facebook defended its policy, saying it “believes political speech should be protected.” If Warren “wants to say things she knows to be untrue, we believe Facebook should not be in the position of censoring that speech,” a spokesperson for the company said. Warren explained her decision to run the ads in a series of tweets Saturday in which she explains her campaign wanted to “see just how far” Facebook’s policy “to allow politicians to run ads with known lies.” This is just one example of how “when profit comes up against protecting democracy, Facebook chooses profit.”

Facebook changed their ads policy to allow politicians to run ads with known lies—explicitly turning the platform into a disinformation-for-profit machine. This week, we decided to see just how far it goes. — Elizabeth Warren (@ewarren) October 12, 2019

Once again, we’re seeing Facebook throw its hands up to battling misinformation in the political discourse, because when profit comes up against protecting democracy, Facebook chooses profit. — Elizabeth Warren (@ewarren) October 12, 2019

Dave Karpf, an associate professor of media and public affairs at George Washington University, tells CNN that the ad has put Facebook in a complicated spot. “Either Facebook doesn’t touch the ad and the ad is therefore noteworthy, or they touch the ad and it’s noteworthy,” he said. “It’s a smart tactical move.”

Facebook came under criticism recently for its decision to allow Trump to run an ad that contains false information about former vice president Joe Biden. While some networks have refused to run the ad, Facebook refused to remove it following a request from the Biden campaign. But Facebook is hardly alone as Google and Twitter also refused to take down the ad that claims Biden promised $1 billion to Ukraine if the country fired a prosecutor that was investigating a company with ties to his son.