Anonymity Not Security!
Remember Tor is designed for providing anonymity not security of your information/data. It hides you from the site your visiting. The trick is not to use the TOR network for sending any of your sensitive data, if you do want transmit your sensitive data over the network encrypt it! Whether using SSL, SSH or TrueCrypt, anything. For anyone interested in the technicalities in the TOR network I would recommend listening to episode 70 of 'Security Now!' http://media.grc.com/sn/SN-070.mp3