By ABBY LLOYD

Mark Zuckerberg, Facebook CEO, testified before Congress today for the first time at Capitol Hill to answer lawmakers questions about the data hack.

Zuckerberg said he takes full responsibility for what has recently happened with the data hack. As soon as he entered the room, he told Senate, “I started Facebook, I run it, and I’m responsible for what happens here.”

The data hack was started by an American researcher, Aleksandr Kogan, who gathered information from basic profile information of Facebook users. People are very upset because Kogan lied and said that he was “gathering research” but then violated company’s policies by passing the data to Cambridge Analytica.

According to Fortune, this type of data is used to target voters with hyper-specific appeals on Facebook and then that try to change their opinions. Cambridge Analytica is a site that uses “data to change audience behavior.” Basically, data is being leaked about people’s political views on Facebook.

It uses such data to target voters with hyper-specific appeals, including on Facebook and other online services, that go well beyond traditional messaging based on party affiliation alone. This is known as “psychographic” targeting or modeling.

“Here are a few things that we are doing to address this and to prevent it from happening again. First, we’re getting to the bottom of exactly what Cambridge Analytica did and telling everyone affected. Second, to make sure no other app developers out there are misusing data, we’re investigating every app and to prevent this from going forward, we’re making sure they can’t access as much information now.” Zuckerberg, 33.

This has been covered by almost every large news broadcast network, CNN, Washington Post, New York Times, and more.