There's been talk of numerous security holes in the software driving the PSP, which had been exploited by crackers last week. Sony has now corrected the problem, by releasing Version 2.01 of the device's firmware. The update is currently intended only for Japanese PSPs, however.
Sony's PSP site encourages users to download the latest patch, but only if they have a PSP with the system model number PSP-1001. Users who don't have a the model number PSP-1001 are advised against download and installing the patch as the company states there is no guarantee of proper operation with other models of the PSP system.