Remember when Mark Zuckerberg called Facebook users “dumb fucks” for handing their data over IM while at Harvard? If this should have taught 19 year-old Mark anything – anything at all – it's that you shouldn't say anything over messenger.

It's a lesson he seemingly didn't learn, as TechCrunch reports that Facebook deemed it necessary to secretly deleted a whole bunch of his Facebook messages following the Sony Pictures hack in 2014.

The messages, which were sent to former employees and a handful of people outside of the company, no longer appear, and the files have also been removed from Facebook’s Download Your Information tool.

Facebook sighted "corporate security" in the following statement to TechCrunch when challenged about the removal of certain messages.

“After Sony Pictures’ emails were hacked in 2014 we made a number of changes to protect our executives’ communications. 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.”

Removing messages like this is a privilege no other Facebook user has. There is certainly no “retention period”, and Facebook never disclosed removing the messages at the time.

Neither did they inform the recipients, so now all that is left is a one-sided conversation. As the users weren’t notified, TechCrunch says this raises the question of whether it was a "breach of user trust", to which Zuckerberg declined to comment.

In all fairness, he probably has a couple of other questions that need answering at the moment...

Update from Facebook following publication, soon users will also have the ability to delete messages.

A Facebook representative gave the following statement: "We have discussed this feature several times. And people using our secret message feature in the encrypted version of Messenger have the ability to set a timer — and have their messages automatically deleted. We will now be making a broader delete message feature available. This may take some time. And until this feature is ready, we will no longer be deleting any executives' messages. We should have done this sooner — and we're sorry that we did not."