A recent report has shown that the PS3 security measures as they currently are may not be as secure as many imagine. The console which is used for many purchases, and houses sensitive information like your name, address, and even credit card information may be at risk. A single unencrypted text file is being sent to Sony from the console and some are claiming that this data may now be accessed through by network intruders.
The report claims that Sony is now keeping much more detailed records of your virtual fingerprint on the console, and with that more information. The PS3 connection to the PlayStation Network is secured with a SSL implementation. Access to this server is verified by using a list of certificates that are now easily forged and subverted by hackers that utilize the features of custom firmwares.
Source: Ars Technica