There’s a theory that’s been around for as long as the Internet – there are two groups who innovate the fastest with new technology: pornographers and criminals.

That theory recently proved true again, and that’s the genie Facebook is trying to get back into the bottle and the reason Mark Zuckerberg is testifying in front of Congress this week. Facebook’s decision in 2010 to allow developers to use the Open Graph platform to launch apps to access the data of users — and their friends’ — is at the heart of the issue that has caused this crisis.

During the window between when this development platform was open and when it was shut down in 2014, a lot of bad guys flooded Facebook with a lot of skeezy apps. Why shouldn’t they – Facebook was and still is the greatest collection of consumer information on the planet. Among the dicey apps was one which promised to give users a psychological profile of themselves. It was created by Alexander Kogan, who then sold the data he compiled to Cambridge Analytica.

In all, 300,000 people downloaded the app and shared their data with the app, and Facebook being how it was in 2013, that meant Kogan had access to millions of users’ profile information.

If you were a Facebook user in those days and you used an app to tell your horoscope, to find out what your Myers-Briggs profile was, if you were an introvert, an extrovert or a Trekkie, you gave permission to that app to take as much data about you as you had opted to make public.

That’s a lot of information – and information about your friends. Millions of data points which can be used to great audience profiles and benefit brands looking to connect with certain people and make them take certain actions, like supporting a candidate.

While your friends’ data is no longer available because of Facebook’s changes, the specter of the platform sitting on this reservoir of personal profile information is still freaking everyone out. But for Facebook, all of those demographics, Page likes and group memberships create the cash which makes the company go.

Yesterday, Sen. Orrin Hatch (R-Utah) asked Zuckerberg how it was that Facebook made money. The answer from Zuckerberg, “We sell ads.”

Actually what they do is sell the audience. Cambridge Analytica just exploited and innovated off a huge hole in the system which happened nearly ten years ago.

There’s no doubt that there were other bad apps gathering mounds of data during the Wild West days of Open Graph. Their names will bloom up now and then over the coming months. Now that there’s awareness watch out.

Mike Koehler is the founder and chief strategist of Smirk New Media.

Editor’s Note: This is the second blog in a content series by Smirk New Media about the Facebook Cambridge Analytica scandal. Next in Smirk New Media’s We Need to Talk About Facebook series, a thorough recap of how Facebook got here from Strategist Annie Strom. 

Read the next blog in the series here.