Sony has pushed out a firmware update for the PS3, v3.42, which the company claims "includes additional security features". However, according to gamers who have installed the update, the specific features involve blocking the PSJailbreak family of hacks which some owners have been using to circumnavigate the PS3's copy-protection and install titles direct to the console's hard-drive.
PSJailbreak first emerged as a USB dongle a few weeks back, and was followed by numerous copy-cat implementations and even a software-only version. Sony quickly countered with at least one court case banning the PSJailbreak dongle's sale in Australia, but this firmware change seems to be their broader attempt to manage the situation.
For their part, the developers of the software reckon they can bypass the new firmware version and maintain functionality, but as of this moment neither the dongles or the software will work.