Though, it's unclear if Patrick means to include 0.8.4 in his warning, or is just reasoning back from what the fixes in 0.8.4 have revealed about risks for people running earlier versions.
I have started to think it isn't practical to explain how Bitcoin works to non-technical people. For a long time, I tried to explain it to my parents Then, I realized that people don't understand the payment systems they already use (credit cards, debit cards, bank transfers, even cash). They just know that it has value, when numbers go up or down, who to call when something goes wrong, and how to give someone enough information to handle the transfer process for them. The same thing happened with certificate-based authentication / encryption.
Certainly to non-technical people, it's just digital cash that takes a bit of time to hand from one person to another? Isn't that a nearly perfect understanding for someone that doesn't want to know about hashing, blockchains, double spends, etc.?
