From the PlanetXbox360 feature article:
"As you may have noticed, the PlayStation Network has undergone a series of attacks that have forced Sony to take it offline for the past week – and it looks like the outage will be going on for a while longer, as the company tries to figure out what PSN user information was compromised during the attack. Now, for the time being, Xbox Live subscribers aren’t in any danger, though the likelihood of a similar attack hitting the service is right up there. So, to play it safe, we highly suggest following these steps to keep your information safe. It may sound a little unnecessary, but trust us, it’ll save you some headaches in the long run."