Ordinary Facebook users can't delete their messages from recipients' inboxes.

Facebook has been quietly deleting old messages from Facebook CEO Mark Zuckerberg out of their recipients' Facebook Messenger inboxes, the company has acknowledged. This isn't an option available to ordinary users. Users can delete their own copy of a Messenger conversation, but if they do the other party will retain his or her own copy.

"Three sources confirm to TechCrunch that old Facebook messages they received from Zuckerberg have disappeared from their Facebook inboxes, while their own replies to him conspicuously remain," Techcrunch's Josh Constine wrote.

Facebook argues that it has done nothing wrong.

"After Sony Pictures’ emails were hacked in 2014, we made a number of changes to protect our executives’ communications," the company told Techcrunch. "These included limiting the retention period for Mark’s messages in Messenger. We did so in full compliance with our legal obligations to preserve messages."

While deleting the messages may not have been illegal, it is going to raise some eyebrows. For weeks, Facebook has faced criticism for appearing to put its own financial interests ahead of the privacy interests of users in the Cambridge Analytica scandal. Now we're learning that Facebook has essentially created a two-tier system of privacy for Messenger users: Zuckerberg and a handful of other Facebook executives enjoy a limited "retention period" of their messages, whereas the embarrassing messages of ordinary users live on as long as their recipients want to keep them.

Zuckerberg has a history of having old, embarrassing instant messaging conversations come back to haunt him.

"Yea so if you ever need info about anyone at harvard just ask," Zuckerberg wrote shortly after the site's 2004 launch as a social network for Harvard students. "I have over 4000 emails, pictures, addresses, sns."

"How'd you manage that one?" the friend asks.

"People just submitted it," Zuckerberg replied. "I don't know why. They 'trust me.' Dumb fucks."

Presumably Zuckerberg has become more circumspect in recent years, so the deleted Messenger messages probably don't contain anything quite that embarrassing. But with ever-increasing scrutiny into Facebook's business practices, it's not hard to see why Zuckerberg would want to minimize his paper trail.

Looks like it was more a Zuckerbook than facebook :-)