Social media network Facebook now has two billion monthly users, CEO Mark Zuckerberg announced Tuesday. "We're making progress connecting the world, and now let's bring the world closer together," the 33-year-old said on his Facebook page. The announcement comes amidst growing concerns over the company's privacy practices. In May, Facebook was accused of targeting teens who felt "worthless" and "insecure" through customized advertising campaigns, according to the Australian. The teens were as young as 14, and the social media network identified their emotional state by monitoring photos, posts and online activity in real-time.Detailed in a 23-page report marked "Confidential: Internal Only," Facebook reportedly assessed when young people felt "overwhelmed," "nervous," "stupid," "useless, "defeated" and more. It then passed the data onto third-party marketing companies.In 2014, the social media site revealed it had altered the news feeds of more than half a million randomly chosen users in an experiment that analyzed how emotions spread online. It claimed its actions were covered by its terms of service.A February survey showed that more Americans are growing increasingly concerned over lack of digital privacy.Eight of 10 people don't like that they're being tracked by third parties, according to research from Envista Forensics, while 71 percent of people are more concerned about online privacy then they were a decade ago.