Twitter CEO Jack Dorsey interviewed Edward Snowden via Periscope about the wide world of technology. The NSA whistleblower "discussed the data that many online companies continue to collect about their users, creating a 'quantified world' -- and more opportunities for government surveillance," reports TechCrunch. Snowden said, "If you are being tracked, this is something you should agree to, this is something you should understand, this is something you should be aware of and can change at any time." TechCrunch reports: Snowden acknowledged that there's a distinction between collecting the content of your communication (i.e., what you said during a phone call) and the metadata (information like who you called and how long it lasted). For some, surveillance that just collects metadata might seem less alarming, but in Snowden's view, "That metadata is in many cases much more dangerous and much more intrusive, because it can be understood at scale." He added that we currently face unprecedented perils because of all the data that's now available -- in the past, there was no way for the government to get a list of all the magazines you'd read, or every book you'd checked out from the library. "[In the past,] your beliefs, your future, your hopes, your dreams belonged to you," Snowden said. "Increasingly, these things belong to companies, and these companies can share them however they want, without a lot of oversight." He wasn't arguing that companies shouldn't collect user data at all, but rather that "the people who need to be in control of that are the users." "This is the central problem of the future, is how do we return control of our identities to the people themselves?" Snowden said.