Mark Zuckerberg really doesn't want to talk about tracking non-Facebook users, and he's not even sure what this whole "shadow profile" thing is you keep asking about.

During today's testimony in front of the Energy and Commerce Committee, Representative Ben Lujan of New Mexico repeatedly asked the CEO to what extent the company collects data on people who have never had a Facebook account. The only thing Zuckerberg made clear in response was that we weren't going to get a straight answer.

"Facebook has detailed profiles on people who have never signed up for Facebook, yes or no," asked the Congressman.

"Uh Congressman, in in general we collect data from people who have not signed up for Facebook for security purposes to prevent the kind of scraping that you were just referring to," responded Zuckerberg.

But Lujan wasn't done. "So these are called 'shadow profiles,' is that what they've been referred to by some," he pressed.

"Congressman, I'm not, I'm not familiar with that," answered Zuckerberg.

#Zuckerberg faces tough questioning over data collection of people who do NOT have a Facebook account pic.twitter.com/HJEWTLg1Hv — Mashable News (@MashableNews) April 11, 2018

But of course, Zuckerberg must be familiar. The company was forced to issue what it called a bug fix in 2013 after researchers discovered that Facebook's profiles on users included contact data that they had never uploaded. At the time, this was widely referred to as part of Facebook's "shadow profiles" of its users.

The idea that Zuckerberg wouldn't be familiar with what was a major privacy scandal is frankly laughable.

And Lujan had more hard questions for the Facebook founder.

"Do you know how many points of data Facebook has on the average non-Facebook user," asked Lujan.

"Congressman I do not off the top of my head, but I can have our team get back to your afterwards," replied Zuckerberg.

Lujan hammered that point. "It's been admitted by Facebook that you do collect data points on non-average users, so my question is can someone who does not have a Facebook account opt out of Facebook's involuntary data collection?"

Zuckerberg's long and winding answer claimed that non-Facebook users can opt out of any data collection for ads, but then Lujan asserted that in order to see what data Facebook had collected on non-users those people would first have to create a Facebook account.

It's privacy-eating snake chomping down on its own tail. Too bad Zuckerberg appears to be unfamiliar with it as, after all, it's a beast of his own making.