Gamasutra has announced today that the PlayStation Network security has once again been tested, but it hasn't been Sony who has been attacked directly. Sony's SVP and chief information security officer Philip Reitinger stated that account names and passwords collected from other sites have been tested against the network and 93,000 accounts have been accessed. Sony has already shut these accounts off temporarily and contacted the owners. Reitinger has gone on to say "only a small fraction of these 93,000 accounts showed additional activity prior to being locked. We are currently reviewing those accounts for unauthorized access, and will provide more updates as we have them."
Sony has said that, unlike last time, no credit card numbers were lost. The company will refund any account that had unauthorized purchases made. The rest of the Gamasutra article can be found here.
Make sure you check your accounts, and maybe change up your passwords for more than just the PSN.