20 Facts You Probably Don't Know About Facebook.

1. The average user has 130 friends

Are you worried about your popularity? The average number of friends on Facebook is 130, and women tend to have somewhat more than men. Yet despite having hundreds of friends, most people only interact regularly with 4 to 7 people.

2. Over 25% of users have already been dumped via Facebook

A June 2010 survey of 1,000 Facebook users -- 70% of whom were male -- found that 25% had been "dumped" via Facebook (via their significant other updating his or her relationship status).

Twenty-one percent of those surveyed said they would end a relationship by changing their Facebook relationship statuses to "single." While worrisome, the survey does show the majority of people do not split up via Facebook.

3. Facebook doesn't allow breastfeeding photos

Facebook, the popular social networking website, provoked a squall of maternal wrath when it yanked photos of breastfeeding babies that women had posted on their personal profiles because it deemed them a little too revealing. This, by the way, from a website that allows photos of women in thongs and bikinis and of couples making out; it has even accepted paid advertising for a dating website that featured a topless model. (The topless ad was taken down after angry women noted the hypocrisy.)

4. Facebook causes 1 in 5 Divorces

It used to be the tell-tale lipstick on the collar. Then there were the give-away texts that spelled the death knell for many marriages. But now one in five divorces involve the social networking site Facebook, according to a new survey by the American Academy of Matrimonial Lawyers.

5. Al Pacino was the first ‘face' on Facebook

Remember that sad-looking blue guy on Facebook's homepage who used to stare you down every time you went to log in? They did away with him in 2007, so if you were late to the social networking party, then you probably have absolutely no idea what we're talking about. Anyway according to David Kirkpatrick's The Facebook Effect , it turns out that that guy in the logo, created by Zuckerberg's friend and classmate Andrew McCollum, was none other than a young Al Pacino “covered with a fog of ones and zeros — the elementary components of digital media.” Crazy, right?

6. 36% of users check Facebook, Twitter or texts after sex

Lighting a cigarette after sex? That's soooo last season. A recent study suggested that social networks are becoming an increasingly important part of young people's lives. Among under-35s, 36% admitted to "tweeting, texting and checking Facebook after sex." Forty percent of respondents admitted to doing so while driving, 64% said they do so at work, and 65% use these communication channels while on vacation.

7. Over 350 million people suffer from Facebook Addiction Disorder

Facebook Addiction Disorder (FAD) is a term introduced by US phychologists for those who are addicted to Facebook and their life is really affected by their uncontrolled activities on Facebook. The most common effects are the loss of productivity, the inability to concentrate, the superficiality of friendships as well as isolation in the extreme cases. It has been said that approximately 350 million people are suffering from the disorder.

8. 64% of Facebook users visit the site on a daily basis.

Recent studies shows that more than 64% of facebook users visit the site everyday.

This is according to a 2014 Pew study. That’s up from 51% in 2010.

9. Burger King gave away free burgers to users who unfriended people on Facebook

In January 2009, an advertising campaign from Burger King titled “WHOPPER Sacrifice” rewarded Facebook users a free “Angry Whopper” for publicly deleting 10 friends, who would then receive a blunt message informing they were deleted for a free hamburger. The campaign, conceived by Burger King agency Crispin Porter + Bogusky and executed by Refresh Partners, used the tag line “Friendship Is Strong, but The Whopper Is Stronger.”

At press time the application had been downloaded more than 55,000 times and over 250,000 ‘friends' were sacrificed.

10. A man was arrested for openly asking his 13-year-old daughter for sex over Facebook

On perhaps one of the worst crimes perpetrated in Facebook, a Pennsylvania father was arrested for allegedly asking his teen daughter for sex over Facebook. John Forehand, 39, referred to himself as "Bad Daddy" in the online correspondence with his 13 year-old daughter, in which he openly propositioned her and made explicit sexual suggestions. Forehand told his daughter he had been having "inappropriate" dreams about her, and wrote to her, "I'll take very good care of my little girl."

The girl told her mother about the inappropriate Facebook messages, and she then alerted the police. The police captured Forehand by tricking him into coming to what he believed would be a meeting with his daughter. How sick is that?