Apparently it’s now a thing for teenagers to set themselves on fire and share it on social media -- it’s called the “fire challenge,” although “natural selection” might be a better term for it. Thankfully most teens probably won’t feel compelled to self-immolate online, but there’s still plenty of reason to worry about social media’s broader impact on young people, as a whole series of depressing studies and reports have recently illustrated. The results of a new survey by We Heart It, first reported by Time, reveal widespread cruelty in teen girls’ and young women’s online communities, driven by unhealthy group dynamics and personal rivalries. We Heart It surveyed 5,000 female social media users, ages 13-24, and found that 66% had experienced bullying on Facebook, while 19% said they had been bullied on Twitter, and 9% were bullied on Instagram. Meanwhile fully 59% of respondents said they feel like they don’t fit in on Facebook -- a paradoxical result (the majority of people don’t fit in?) which would be funny if it weren’t so sad -- while 32% said they same thing about Twitter, and 30% on Instagram. Another study by researchers at Australian National University’s National Institute for Mental Health Research, analyzed from Weibo, the Chinese version of Twitter, and determined that people who use social media late at night are much more likely to suffer from depression. The study looked at Chinese users who were more active than average between 11 pm and 3 am at night, and found that late-night were more likely to use words such as “death, depression, life, pain and suicide,” suggesting they were dealing with major depressive disorder. Concerns about “Internet addiction,” and especially social media, have given rise to a new industry in China and India, in the form of Internet detox camps for teenagers whose parents are concerned about flagging academic performance and social dysfunction. According to news reports this week, there are over 250 such camps in China, which tend to emphasize physical exercise and a “cold turkey” approach, totally banishing Internet from kids’ lives for up to six months. In June, India’s first “Internet de-addiction center” opened in Bangalore, the center of India’s dotcom boom. As in China, most patients seem to be young middle-class people whose parents have tried, unsuccessfully to get them to cut back on Internet use because of poor academic performance. According to the report one patient, an 18-year-old girl who had been using the Internet for up to eight hours a day, began stealing money and visiting cyber-cafes to get her daily fix.