What you're writing may not be as private as you may think.
That's what happened to Dr. June Talvitie-Siple, a math and science teacher at Cohasset High School in Massachusetts. The teacher thought she was writing to an audience of only 50 friends and family members on the popular networking site when she described students as "germ bags" and school parents as "snobby" and "arrogant."
But her words, including a post that she was "so not looking forward to another year at Cohasset Schools," were actually a lot more public than she thought.
When the district superintendent and school committee found out she posted the comments on Facebook, Talvitie-Siple was asked to resign from her $92,636-a-year job.
Talvitie-Siple, now unemployed, appeared on "The Early Show" Friday with more on her cautionary tale about Facebook privacy settings.
"Early Show" co-anchor Harry Smith commented that her words, when taken in context, are "far less incendiary" than initially perceived.
"Thank you. I appreciate that," Talvitie-Siple replied.
Taking on her comment that called kids "germ bags," for instance, Talvitie-Siple said she made that comment in light of the fact that she was sick most of the last school year, ending the year with pneumonia.
She said, "It was a joke."
As for the parents, Talvitie-Siple said she was referring to the turmoil in the school district among the teachers union, the administration, the school committee and the community at large.
As for her privacy settings on Facebook, she says she had them set to block out students and the wider Facebook community, but when Facebook made changes to its privacy settings recently, she was defaulted to a more open setting.
"You had to really be paying attention (on Facebook)," Talvitie-Siple said. "I was working 12, 14 hours a day, very, very busy. You know, even if an e-mail ... like that did come across, I didn't see it. If it had been on Facebook -- I actually don't use Facebook that much."
"Probably be using it a lot less in the future," Smith said.
"Probably!" Talvitie-Siple replied.
She says people need to be very diligent about their online activities.
"I am a technology person and yet I got caught short," she said. "And even today, I was looking at the newspaper, and there was an article about coming out. That's a GPS function, that if you have that on your cell phone for Facebook, anybody can find out where you are at any given moment. And you have to opt out, not opt in."