Mark Zuckerberg says that Facebook is going to investigate other app makers to see if anyone else was selling data they collected but did not mention that their entire business model is based on collecting this information and selling it to third parties.

Facebook is not the only free service with business models which is based on collecting data about it’s users and selling it to third parties.

Read more here: https://www.theatlantic.com/technology/archive/2018/03/data-misuse-bigger-than-facebook/556310/