The simple answer is that they are deleted, it seems, according to the New York Observer yesterday.
A photographer based in Zurich has accused Flickr of accidentally deleting his account, and the 4,000 photos, copyright information, tags and comments in the process.
While the photographer has hard copies saved elsewhere, Flickr is trying to rectify the situation as best it can.
In an apologetic email sent by Flickr to the photographer, it states the account itself could be restored but the photos may not be able to be recovered.
"I can restore your account, although we will not be able to retrieve your photos. I know that there is a lot of history on your account-again, please accept my apology for my negligence. Once I restore your account, I will add four years of free Pro to make up for my error."
Though I empathise greatly with the photo journalist in question, I have to give credit to Flickr and their apparent 'full wipe and delete' policy of cloud stored data.
As considered before, Facebook does not erase user-deleted content. Once you hit delete, you can still access it directly through URL hotlinking for months, and in some cases years after you first 'erased' it.
But if Flickr has in fact completely deleted this photographer's pictures, then while it is a mistake on their part, at least 'delete' actually means delete.
Should 'delete' mean an irreversible delete?