According to the BBC, hackers gained access to a rumored 120 million Facebook accounts, of which they've reportedly put private messages from about 81,000 handles, up for sale on the black market. Although the BBC was quick to report on the "breach of confidentiality," they also suggest the final numbers might be misleading.
Facebook says that although personal data for each user doesn't appear to have been compromised, they were able to find a probable access point for the intrusion: fraudulent "browser extensions."
"We have contacted browser-makers to ensure that known malicious extensions are no longer available to download in their stores," said Facebook executive Guy Rosen. "We have also contacted law enforcement and have worked with local authorities to remove the website that displayed information from Facebook accounts."
This mass intrusion is made interesting because it's kind of a blind gesture. In theory, one criminal is offloading a mystery bundle of information that could either turn into a dead-end or a total goldmine, depending on what the 81,000 messages yield.
For example, if the Facebookers implicated in the "hack" happened to share information such as personal addresses, telephone numbers, or banking information (you never know) then the illegal transactions holds more than just its nominal value. May this be a lesson to all: reducing your online footprint is never a bad idea.