Facebook buying Instagram for $1 billion

Facebook announced Monday that it will buy Instagram, a popular mobile-only photo-sharing app, for $1 billion.

Instagram has garnered attention as its user base increased rapidly, from 1 million users in January 2011 to 15 million in December 2011, and 30 million users now, according to Business Insider. It marks Facebook's largest ever acquisition of a company or product by number of users.

Facebook CEO Mark Zuckerberg said in a press release the site is "committed to building and growing Instagram independently," adding that Facebook plans on preserving users' ability to post to other social networks, to opt out of sharing Instagrams on Facebook, and to have followers separate from a Facebook account.

The social network said it would use its engineering and infrastracture strength to help Instagram grow.

As Facebook seeks to get in on Instagram's buzz, some users may be less pleased. According to a recent poll, photo apps like Instagram are now the worst annoyance on Facebook, beating out other people's baby photos. As much as 20% of Facebook users reported deleting friends specifically because of annoying photos.