Terrorism “expert” Steven Emerson is sorry for implying that whole British cities live under tyrannical Muslim rule on a Fox News program Sunday. He had painted a frightening image of British libertines forced to cover up whilst being chased by shalwar kameez–clad men in their hometowns — and one that is entirely false. Even British prime minister David Cameron called him “a complete idiot.”

“In Britain, it’s not just no-go zones, there are actual cities like Birmingham that are totally Muslim where non-Muslims just simply don’t go in,” Emerson said Sunday. “And, parts of London, there are actually Muslim religious police that actually beat and actually wound seriously anyone who doesn’t dress according to religious Muslim attire.” (He also apparently fails to realize that Muslims are not a monolithic group, and “religious Muslim attire” doesn’t have a universal meaning. And, even if one were to buy into the foolish claim that British Muslims don’t value individual liberties or European liberalism, Emerson is wrong on a statistical level, too: Muslims only make up about a quarter of Birmingham’s population.)

Yet he couldn’t have done it all without the help of Fox News anchor Jeanine Pirro. When she wasn’t staring straight ahead, looking mildly terrified on the split-screen as Emerson spewed nonsense, she was egging him on. “You know what it sounds like to me, Steve?” she asked. “It sounds like a caliphate within a particular country.”

By Monday, though, Emerson’s PR team had partly changed course, and he — the man who claims to run “the world’s most comprehensive data center on radical Islamic terrorist groups” — apologized for the “terrible error” of what he said about Birmingham. Emerson didn’t take back his panic about no-go zones in London and western Europe, though, and no word yet on whether Pirro will rein in her own fearmongering.

But the apology didn’t happen before Emerson’s ill-advised lie birthed the popular Twitter hashtag #FoxNewsFacts, which mocks his alarmist language about Islam:

All post boxes in #Birmingham have been forced to wear red burqas. #foxnewsfacts pic.twitter.com/gUaPMs23ZR — Matthew Ward (@HistoryNeedsYou) January 12, 2015

In Birmingham, the local death squads go by the name of Quran Quran. #foxnewsfacts pic.twitter.com/xHXFtPUHxZ — David Jack (@DamJef) January 11, 2015

This is a picture from the Aston Villa-Birmingham derby. #FoxNewsFacts pic.twitter.com/qUn9gQFyyk — Robin Wigglesworth (@RobinWigg) January 11, 2015