An unknown group has caused quite a hassle by publicly posting information about tens of thousands of user accounts.
A 4.5MB text file (passlist.txt) was uploaded to a Finnish website earlier today. The file contains usernames, e-mail addresses, passwords and uncracked password hashes of almost 79,000 user accounts. These accounts are mostly from different Finnish web forums.
It's quite trivial to find the correct password based on the password hash, assuming the password is "easy" and can be found from a password dictionary. The passlist.txt file claims that the hack was done by two Swedish hackers but this has already been disputed.
The case exhibits some resemblance to an incident six weeks ago, where Swedish hacker Dan Egerstad published hundred passwords to different embassies and government organisations. However, in that case the information was stolen by Mr. Egerstad by running rogue TOR exit node servers.
In today's case, the information has been stolen by unknown parties – most likely by hacking the servers of several Finnish web forums: that's pretty much the only way to gain access to the password hashes.