Students use Facebook as a means of meeting new people as well as reconnecting with old friends.

However lately it’s been a place for a mix of teachers, students and, well, Facebook. While its great to say hello to your teachers it can be dangerous ground in some cases, like the ones in New York City.

According to the New York Post, one teacher left comments like, "This is sexy," under girls' pictures, school officials told the paper. Others made lewder comments, and some even used Facebook to initiate real-life relationships with students, it said. All three of them have been fired.

In Pennsylvania, a teacher was suspended after students saw photos of her on Facebook posing with a stripper. In Florida, a teacher was suspended after posting a note saying he "hated" his students and his school. A Washington, D.C., special education teacher faced scrutiny after the phrase, "You're a retard, but I love you," was found on her personal page. In August, a 54-year-old math and science department supervisor was fired after she called her students "germ bags," on Facebook and described parents as snobby and arrogant. And news stories have chronicled the discoveries of photos showing teachers in compromising situations such as drinking alcohol in glorified ways.

Facebook can be used in a good way by staying in contact with teachers after graduation. In the Houston area, many districts block access to social networking sites on campus computers, but they don't have policies addressing after-hours use between educators and students.

Houston high school teacher Lesley Guilmart said she finally caved last year and, at the urging of former students, created a profile on Facebook.

"It's kind of addictive," she admits. "I'm interested in my students, and I like to hear from them. I have a couple of kids in college now who have sent messages thanking me for helping prepare them. I had a kid send me a message asking advice about picking a major."

So far, Guilmart has become virtual friends with several former students and even linked up with an old teacher from North Carolina. She said she wouldn't mind connecting with her current students at Houston ISD's Reagan High School — if they asked.

Aware of privacy concerns, Guilmart, 27, said she doesn't go searching for her students online.

"If they want to 'friend' me, they can," she said. "My Facebook is entirely PG. There's no cursing. There are no photos of me having a good time on the weekend — nothing like that."

To be on the safe side it’s a good idea to wait until you’re in college to befriend your teachers on Facebook. Some schools have students wait until they’ve graduated to friend them on the social networking site. That is probably the right thing to do to avoid getting into trouble with the law. Some schools have teachers befriend their students to where they can give homework due dates and stuff that's school related. That can help students who miss a certain day catch up on any late work.