If you have an older PS3 and logged into the PSN last night, you may have noticed a glitch on your system. Here are a few links to the problems that occured and Sony's official statement today with some answers.
http://ps3.ign.com/articles/107/1072875p1.html
http://ps3.ign.com/articles/107/1073283p1.html
http://ps3.ign.com/articles/107/1073007p1.html
http://ps3.ign.com/articles/107/1072875p1.html
http://ps3.ign.com/articles/107/1073283p1.html
http://ps3.ign.com/articles/107/1073007p1.html