Two men made trouble—and stirred up a social-media frenzy—on the third day of the Conservative Political Action Conference by conducting a literal false-flag operation.

Jason Charter, 22, and Ryan Clayton, 36, passed out roughly 1,000 red, white, and blue flags, each bearing a gold-emblazoned “TRUMP” in the center, to an auditorium full of attendees waiting for President Trump to address the conference. Audience members waved the pennants—and took pictures with them—until CPAC staffers realized the trick: They were Russian flags.

The stunt made waves on social media, as journalists covering CPAC noticed the scramble to confiscate the insignia.

No joke, someone has been handing out Russian flags that say #Trump on them. And people are waving them.#CPAC2017 pic.twitter.com/CDZS5oEqyL — Maya Shwayder (@MayaErgas) February 24, 2017

A section of people in the back of #CPAC2017 waving Russian flags -- a staffer just came and demanded they all be handed over. pic.twitter.com/mZVoVUqudn — Tim Alberta (@TimAlberta) February 24, 2017

Clayton himself was photographed outside, holding up a larger version of the flag:

“Most people didn’t realize it was a Russian flag, or they didn’t care,” Charter told me in a phone interview. He and Clayton had purchased tickets to CPAC for the day the president was scheduled to speak, and managed to disperse the flags with surprising ease among the crowd.