Courtney Keniston is mild-mannered around friends at Centennial High School in Circle Pines, so her bold statements on Facebook often surprise them.
For every benign "mmm, bacon and cinnamon rolls" post about breakfast, the 14-year-old offers her opinions about religion or relationships.
"When I feel really strongly about something," she said, "I'll post something about it."
Social media allow adolescents and teens to be expressive -- and in Courtney's case both she and her parents believe it is constructive.
But a recent study by the Girl Scouts found that isn't always the case when girls go online. Surveying 1,000 teen girls who use social media, the organization found those with low self-esteem were more likely to project themselves through Facebook, Twitter or MySpace in ways that didn't match their personalities.
Of these girls, 22 percent portrayed themselves through social media as "sexy" and 35 percent presented themselves as "crazy." One in three said their online persona doesn't match who they really are.
All girls were more likely to present themselves as funny or social and less likely to present themselves as smart or kind.
Trouble is, girls who try to boost their image in the virtual world suffer problems in the real world that they don't anticipate, said Sabrina Lee Sanchez, program implementation manager for Girls Scouts of the USA. Classmates might recognize exaggerations and use them as a source for teasing or bullying. Girls portraying themselves as sexually active or drinkers might be pressured into those activities.