Any security scheme is only as good as the weakest link. And frequently that weak link is the user. No matter what you tell some of them, they just lack the ability to use any form of analysis prior to entering their credit card into a page or downloading spyware-ridden useless software. It's even worse when ordinarily intelligent people become blubbering idiots within a foot of a personal computer.

On AIM ... I use Gaim under Windows and Linux, and AdiumX on the Mac. I have a lot of friends that use Trillian in Windows. And none of them have an encryption scheme that will work with any other client. Would be nice to see at some point.