The Momo Challenge gained the public's attention in July 2018, when it was noticed by a YouTuber, Targeting teenagers, people presenting themselves as "Momo" on WhatsApp messages try to convince people to contact them through their cell phone. As with other Internet "challenges" such as Blue Whale, players are then instructed to perform a succession of tasks, refusal to do so being met with threats. Messages are subsequently accompanied by frightening or gory pictures.
Although authorities have not confirmed any physical harm directly caused by this "challenge", police forces and school administrations on several continents have issued warnings about the Momo Challenge and repeated common advice about Internet safety. WhatsApp is encouraging its users to block phone numbers engaging in this practice and to report them to the company.
Commenting on the numerous rumours of suicide related to the Momo Challenge, web security experts and people studying modern myths have stated that the phenomenon is likely a case of moral panic: a sensationalised hoax fueled by unverified media reports. Benjamin Radford says "the Blue Whale Game and the Momo Challenge have all the hallmarks of a classic moral panic", "fueled by parents’ fears in wanting to know what their kids are up to.