Facebook is the world's most popular social networking site with more than 500 million active users.And most students take classes focus on Facebook than learning in the classroom.
Although they are fun, they are very distracting and could get in the way of potential schoolwork and affect your grade. This is best demonstrated as kids with 3.0-3.5 gpa have a facebook/use it frequently and kids with 3.5-4.0 gpa don't have one/don't use it.