The UK Home Office has denied entry to YouTube commentator Cenk Uygur and Twitch streamer Hasan Piker, preventing their participation in scheduled SXSW London talks this week.

The ban on the left-wing commentators has shocked many across the political spectrum.

The United Kingdom’s Home Office said Piker and Uygur were blocked from entering the country because their presence “may not be conducive to the public good.”