A couple wakes up to a horrible smell in their hotel room and find a body under the mattress. A college student wakes up to find her roommate dead and a message scrawled on the wall. The Candyman crawls through mirrors to reach his victims. You know all these urban legends. But there might be more truth to them than you realize. Then there’s the more recent Blue Whale challenge. Did dozens of adolescents and teenagers really die because of an internet challenge?

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Blue Whale: What is the truth behind an online 'suicide challenge'?