I think the movie was loosely based on the story of Meagan Meier. She was a 13 yr old girl who hung herself. She was bullied by a friend's mother, Lori Drew, through a fake MySpace account. It's sad. What mother does something like that.
The movie "Sexting In Suburbia" is not based on a true story. It is a fictional movie about a young girl who commits suicide after her nude picture she had sent to her boyfriend went viral. It is later discovered that the picture was posted by her close friend out of jealousy.
While the exact plot isn't a true story, it has a lot in common with the true story of Phoebe Prince, a girl who lived in South Hadley, MA. She was bullied so badly that she committed suicide, and her parents fought to press charges against the students that were the source of the harassment. The main difference is that I don't believe "sexting" was involved in Phoebe's story, but many things in the movie reflect it. The towns they refer to (Westfield, Cummington) are real places in Western MA, near South Hadley. Phoebe's grades did fall, and she did have a shift in mood and behavior. Short answer: technically, no, but in some ways, yes. Hope this helps!