There are more than 955 million Facebook users, and it could hurt you to not be one of them.

Some psychiatrists and employers now find it suspicious for an individual to keep off Facebook, reports The Daily Mail. That's because for today's young generation, having Facebook is considered "normal," while opting out is considered "abnormal."

Employers may suspect that an applicant's absence from the social network means the account is so full of offensive material that it had to be deleted. After all, 90% of recruiters check out candidates' online profiles.

Similarly, psychologists see Facebook activity as a reflection of a healthy social life.

"The Internet has become a natural part of life," psychologist Christopher Moeller told Germany's Der Taggspiegel. "It's possible that you get feelings of positive feedback through online friends." [Translated from German]

In excess, Moeller says, Facebook interactions can reinforce feelings of social anxiety experienced offline.

As the German magazine points out, both suspected Aurora theater gunman James Holmes and the Norwegian massacre shooter Anders Behring Breivik share an absence from Facebook. The publication went as far as to say that Facebook abstainers have reason to be suspected mass murderers.

The two shooters had online footprints on more obscure social networks — Breivik on MySpace and Holmes on Adult Friend Finder.

Do you find it suspicious when you meet someone who's not on Facebook? Do you think being active on Facebook reflects a healthy social life? Let us know in the comments.

Image courtesy of iStockphoto, RapidEye