Following the Brussels attacks on March 22, 2016, the pro-ISIS hacking group Caliphate Cyber Army posted messages on its official Telegram channel calling on ISIS supporters to “storm” trending hashtags on social media with celebratory posts regarding the attacks. The group wrote: “NOTICE: Please take part in this online battle in twitter and storm the trending hashtags we provided you with any information from dawlah [ISIS]. Be it a video, images, news etc. Post and post and you have your ajr [reward] from Allah.” The hashtags provided were #Brussel, #Brussels, #Bruxelles, and #Brusselsattacks.
Another post read: “#Announcement: In a few moments the raid is going to start. We are posting as much as we can with these hashtags… This is top priority now, need to fill our stuff into the brussels hashtag. Get ready, we need everyone!!!”
Source: Caliphate Cyber Army Telegram channel, March 22, 2016.