Polytechnic High Principal Gerardo Loera is a big fan of social media, posting everything from football scores to schoolwide test results on Facebook and Twitter for students, parents and the world to see.

He even includes a live feed of his tweets, usually typed from his cellphone, on the school's website.

"It's just such a useful and immediate way to disseminate information to my school community in a very quick way," Loera said.

"In a few minutes one of my messages can reach thousands of people and if something I post gets retweeted ... well then Poly can be read about all over the country."

But not all uses of social media by teachers and administrators are seen in such a positive light. School