As surely as night follows day, as surely as "meh, not a game" comments follow enthusiastic posts about Proteus or Dear Esther, most every big online game will at some point suffer a scary hack. Latest to fall prey to Internet Badmen is SOE's Planetside 2, or at least the ProSiebienSat EU-run aspect of it. The outsourced operators reckon their encrpytion tech means player details are likely safe, but someone has indeed found a way to access "one of our systems" so players are advised to do the password-changing fandango.
Say they in a public statement, "We have detected that there recently has been unauthorized third-party access to one of our systems. The possibility that your data (Email address and password) has been accessed by an unauthorized third party cannot be excluded. We were able to detect the problem promptly and took all necessary actions to rectify the issue."
They have mailed everyone they believe might have been affected, but if you want to be on the safe side, you know what to do. Additionally, some accounts have been temporarily suspended in the name of ULTIMATE SECURITY, and if that's one of yours you can reactive it here.
What a revoltin' development this is. Hopefully nothing horribad will happen as a result.