The release of a video depicting the purported beheading of American photojournalist James Foley has prompted a backlash against propaganda released by militants with the Islamic State, the group that claimed to have executed him.

The hashtag #ISISMediaBlackout began trending shortly after the video’s release on Tuesday, as Twitter users urged others not to share the video or any other graphic images released by the militant group. The hashtag references one of the group’s names, the Islamic State of Iraq and Syria, and was created shortly after the video was released. It appears to have originated with a woman using the Twitter handle @LibyaLiberty.