What are the biggest negatives of using social network sites like Facebook etc?

[Jonny Lapointe]

They keep all of your information and posts on documentation forever, so even though other people may not be able to see in when it is posted, someone who is in authority, such as an employer or the police, can request a background information check from previous Facebook accounts, so the employer can look through previous posts and such to decide on hiring you. Basically, they are fine to use, as long as you don't get addicted, and you keep your posts and information polite and mannerly.