In April, an Azusa English teacher found herself placed on leave and pulled from a student trip to Europe after posting vulgar comments and references to drug and alcohol use on her Facebook account.
In August, a gay water polo coach at Charter Oak High School was fired after a parent complained about photos of him online posing with drag queens.
And last week, a preschool teacher in the United Kingdom was banned from the classroom for two years after officials discovered she had created an elaborate Facebook scam intended to fool her ex-boyfriend into believing she had given birth to his child and gone to Australia.
Experts say conflicts such as these are becoming increasingly common as more people embrace social media. And school districts are struggling to produce policies on how to handle such situations.
"I think because of the personal nature of social media, it's raising new questions no one ever thought about before," said Jane Ballinger, a professor of communication at Cal Poly Pomona.
A big part of the problem, Ballinger said, is that many people seem to abandon common sense when posting comments or photos online. She said research has shown that there's something about social media networks that leads people to ignore the "filters" they normally use to keep their private lives out of public view.