Facebook officially now has over 1 billion active monthly users, a new milestone for the world's largest social network.

The update to the size of Facebook, founded only in 2004 from a college dorm room, was announced by founder and CEO Mark Zuckerberg in a statuts update on the morning of October 4.

This morning, there are more than one billion people using Facebook actively each month.

If you're reading this: thank you for giving me and my little team the honor of serving you.

Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in my life.

I am committed to working every day to make Facebook better for you, and hopefully together one day we will be able to connect the rest of the world too.

Facebook hit the long-sought, 10-digit user mark at precisely 12.45 p.m. PT on September 14. Approximately 1 in 7 people on Earth is on Facebook, given the U.S. Census Bureau's world population estimate of 7.04 billion.

Who's the lucky one-billionth user? Not even Zuckerberg's sure if Facebook knows. In an interview with Bloomberg Businessweek's Brad Stone and Ashlee Vance, the Facebook co-founder admits that the claim to 1 billion users is based on an estimate, not a true count.

"Doing data analytics at this scale is a big challenge, and one of the things you have to do is sample," Zuckerberg told Stone and Vance. "So it’s funny, we were all sitting around watching us get to a billion users but it was actually just a sample of the users. It’s like you’re not going to try to pull a billion rows from a database, so you’ll pull a sample and project out."

Along with active monthly users, Facebook made several other metrics public in a Word document (download here) published along with Zuckerberg's post.

A majority of Facebook users -- 600 million -- are using mobile phones to log on to the social network, Facebook reports. Since becoming a publicly traded company in May, investors have doubted the company's ability to sell ads on mobile phones as its users increasingly check status updates and upload photos from phones instead of desktops or laptops. Since initially selling for $38 in May, Facebook's stock price has plummeted to $21.83 as of October 3.

The median age of members just joining Facebook, originally founded as a social network exclusively for college students, continues to fall. During the week Facebook hit 1 billion users, the median age of a new member was 22, down from 23 when Facebook hit 500 million users in 2010 and 26 when it hit 100 million users in 2008.

Facebook's servers are currently storing 219 billion photos from users. With 265 billion uploaded at one time or another, about 17 percent of all photos ever put on Facebook have been deleted. (That's a lot of embarrassing drunken nights.)

Some other statistics announced by Facebook:

  • 140.3 billion friend connections since 2004.
  • Over 1.13 trillion "Likes" since the button was added in 2009.
  • 62.6 million songs have been played 22 billion times. According to Facebook, that's 210,000 years of listening.

Related on HuffPost:

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  • Thou Shalt Not... Act Like Bernie Madoff

    "You will not engage in unlawful multi-level marketing, such as a pyramid scheme, on Facebook." OK, so Facebook doesn't mention of Ponzi schemes specifically, but lying, cheating and scamming are definitely out. Leave the crookery to the pros on Wall Street and stick to raising pixelated chickens on your virtual farm. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Be A Convicted Sex Offender

    "You will not use Facebook if you are a convicted sex offender." 'Nough said. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Play Facebook God

    "You will not provide any false personal information on Facebook, or create an account for anyone other than yourself without permission [...] You will not create more than one personal account." No Facebook profiles for dogs, no automated bots, and no accounts for 2-month-old children. Hey, wait, we kind of like this rule. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Harass Thy Neighbor

    "You will not bully, intimidate, or harass any user." Cyberbulling has become a hot topic as social media usage continues to expand. In a recent U.K. court case, <a href="http://www.huffingtonpost.com/2012/06/08/nicola-brookes-facebook-cyberbullying_n_1580442.html" target="_hplink">Facebook was ordered to reveal the identities</a> of several bullies who had set up fake Facebook accounts to harass a 45-year-old mother. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Be Under 13

    "You will not use Facebook if you are under 13." Not a teenager yet? Sorry, no dice. <a href="http://www.huffingtonpost.com/2011/03/23/facebook-underage-users_n_839437.html" target="_hplink">In 2011, the chief privacy adviser of Facebook said</a> that an average of 20,000 underage Facebook accounts are shut down daily. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Spam Or Hack Facebook

    "You will not post unauthorized commercial communications (such as spam) on Facebook [...] You will not upload viruses or other malicious code." That means you, hackers and pushers of penis-enlargement pills. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Have Free Speech

    "You will not post content that: is hate speech, threatening, or pornographic; incites violence; or contains nudity or graphic or gratuitous violence." The lines blur a little with this commandment. While the policy is meant to curb inappropriate activity, opinion is split over what makes a post unsuitable. Perhaps surprisingly, if you were to compare <a href="https://twitter.com/tos" target="_hplink">Twitter's terms of service</a> with Facebook's, you'd see that Twitter currently has no policy on hate speech. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Post Thy Neighbor's Private Data

    "You will not post anyone's identification documents or sensitive financial information on Facebook." This one should be common sense. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Be A Digital Salesman

    "You will not use your personal timeline for your own commercial gain (such as selling your status update to an advertiser) [...] You will not sell user data [...] You will not sell, transfer, or sublicense our code, APIs, or tools to anyone." So basically, no, you cannot profit from Facebook unless Facebook's getting a cut. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>

  • Thou Shalt Not... Encourage Violation To These Rules

    "You will not facilitate or encourage any violations of this Statement or our policies." Whatever you say, Facebook. You've got the whole world in your hands. Taken from Facebook's <a href="https://www.facebook.com/legal/terms" target="_hplink">Statement of Rights and Responsibilities</a>