Steam Forums got hacked.

[yottabyte]

Lulzsec died this summer when that 19 year old was arrested in the UK. I'm guessing either he was the only one calling himself a group (how cute) or all the others got scared when they saw him in the newspaper.

Nonetheless, it's nearly impossible to get the CC info. At least if Steam aren't nutheads.
First of all, you need to know what kind of encryption was used. This is only stored in server files, so you need to actually get access to the file system, not just the database.

If you somehow manage to do that, you still need to decrypt the data. If they used some easy encryption like md5, one string could take perhaps an hour to decrypt on a decent computer. If they used some advanced custom encryption, decrypting one string could take years.