Of all President Trump’s idiosyncrasies, his ready embrace of conspiracy theories and dubious news items is one of the most baffling — and potentially dangerous. As a candidate, he infamously appeared on the Infowars radio show hosted by Alex Jones, the well-known conspiracy theorist, who famously advanced the preposterous claim that Hillary Clinton was part of a child sex-trafficking ring run out of a Washington, D.C., pizzeria. A North Carolina man subsequently shot up the pizzeria in question, with a very real assault rifle. Nevertheless, Trump has reportedly still been seeking advice from Jones, whom he has described as a “nice guy” with an “amazing” reputation.

President Trump’s susceptibility to conspiracy theories and questionable news items took an even more reckless turn Tuesday, when he shared with his millions of Twitter followers incendiary videos from a right-wing British anti-Muslim party called “Britain First.” The three videos posted by the group’s deputy leader, Jayda Fransen, and retweeted by Trump, were titled “Muslim migrant beats up Dutch Boy on crutches!,” “Muslim destroys a statue of the Virgin Mary!,” and “Islamist mob pushes teenage boy off roof and beats him to death!”

While the origin and context of the videos have yet to be verified, their promulgation by the president of the United States drew widespread condemnation. Blowback from videos posted online has had deadly consequences, including in 2011, when two American soldiers were killed by a young Muslim immigrant in Germany.