A lot happened this week in social media: while Twitter keeps trying to be more user-friendly, we found out that Instagram is more popular than Twitter with active smartphone users. Meanwhile, Facebook made a purchase that redefines the company's ambitions and some Pinterest users got hacked -- and flooded with butt pictures. It's Social Media Saturday!

Twitter Keeps Trying 

This week, Twitter announced some changes to the way users can post photos. Instead of one photo per tweet, Twitter is allowing up to four photos per tweet. And instead of tagging friends in your tweet by mentioning their handles in the body of your text, Twitter allows tagging within the photo -- up to 10 tags per photo -- without going against the 140-character limit.

This isn't the first time Twitter took something that users were doing (tagging photos) and internalized it to the system -- Twitter did that with retweets, making them more easily navigable and eliminating the need for users to label tweets with "RT" or "MT." It's all in the service of making Twitter less intimidating for new users.

But speaking of retweets, some other rumored Twitter changes -- which have only been seen in the wild and not unofficial yet -- are getting Twitter users angry, as we previously reported. Twitter often experiments with possible changes by altering a few accounts, and some users have seen their "Retweet" button replaced with the new-user-friendly and Facebook-y "share." (The horror!)

Instagram is Winning

While Twitter keeps trying to popularize its service with the uninitiated, a report came out this week showing that Instagram was more popular with important demographics.

Researcher eMarketer released a report showing that Instagram has grown quite a lot, to an average of 40.5 million active monthly users. Compare that to Twitter, which is set to grow to a little under 38 million active monthly users this year, according to Information Week.

"Instagram usage in the US has ramped up rapidly and is already maturing, reaching regular usage levels nearly matching Twitter's, particularly on smartphones and among millennials and Gen Xers," the report said. "By the end of this year, almost 25% of US smartphone users will snap a photo, slap on a filter, and share their creations with their friends on Instagram on a monthly basis."

Facebook Bares Its Ambition

If you thought Facebook's purchase of messaging service WhatsApp last month for $19 billion was crazy, you ain't seen nothing yet. Facebook this week bought virtual reality and gaming company Oculus, maker of the highly anticipated Oculus Rift virtual reality headset.

Facebook's purchase 'only' took $2 billion, but it's not the size of the bill that made this big news, it's CEO Mark Zuckerberg's reasoning. While assuring Oculus Rift fans that the gaming aspect will continue unperturbed, Zuckerberg explained his long-term plan for Oculus:

"After games, we're going to make Oculus a platform for many other experiences. Imagine enjoying a court side seat at a game, studying in a classroom of students... or consulting with a doctor face-to-face -- just by putting on goggles in your home."

Zuckerberg basically wants to create an entirely new way of interacting with the internet. As we previously noted, this purchase could be what we look back to as the moment Facebook became more than a social networking company with ambitions in emerging markets -- maybe something akin to the next Apple or Google, rolled into one. Or it could be when Facebook realizes Zuckerberg's ambitions are beyond the company's practical reach. We'll see.

Pinterest's Butt-Hack

Not everything in social media was as ground-shaking as Facebook's announcement that it wanted to be the company to build the first beta version of the Matrix. In the world of Pinterest, several accounts were hacked this week and flooded with unwanted images, according to Tech Crunch. Specifically, the spam images were of weight loss ads and rear ends, reminding everyone to always be careful with your account information!