well, at least mozilla uses SSL to encrypt the information, which is the same technology used to send the information over the net to banks, CC numbers to stores etc. So really, it's about as safe as doing all those activities. If you have no problem with online banking, you shouldn't have a problem with (some) of these utilities. Of course, not all programs are created equal, and you should stick to something that is credible (for example, Mozilla is known for having a good implementation of SSL). I can't speak toward these other programs