Shock, horror: loads of publicly-available data has been, er, leaked to the public on BitTorrent.
At first sight, the details look alarming. Canadian security expert Ron Bowes used crawler software to search for information on Facebook users, and then released what he found.
It includes names, unique IDs and URLs for the the profiles of every user who hasn't checked the box saying "Don't allow search engines to find me".
In other words, it allows people to find the home pages of around 100 million Facebook users.
Bowes says his original intention was to search for the most widespread combinations of first names and surnames, as these could be easily used for hacking attacks.
But, he says, when he'd gathered the information he came to believe that the ability to find the name of pretty much everyone on Facebook was an alarming privacy issue.
He doesn't actually seem that alarmed, to be honest.
"Facebook helpfully informs you that 'anyone can opt out of appearing here by changing their Search privacy settings' - but that doesn't help much anymore considering I already have them all (and you will too, when you download the torrent). Suckers!" he says on his blog.
"Once I have the name and URL of a user, I can view, by default, their picture, friends, information about them, and some other details. If the user has set their privacy higher, at the very least I can view their name and picture. So, if any searchable user has friends that are non-searchable, those friends just opted into being searched, like it or not!"
Bowes has made the information available here on his blog, although at the time of writing the site was either down or overloaded.
So, are you on the list? Are you worried?