Sure, I'll agree with you on some of these points, but:
Your phone rings, you pick up. You hear a momentary "click" as you're transferred to an operator, who tells you that you've just won a trip to Jamaica, and that he needs your credit card information to proceed with awarding you your trip. What do you do? Do you assume that he's legit and dole out your credit card to him, or do you use your brain?
The same thinking isn't applied to web objects often enough at all. So, Average Joe may not understand the fundamentals upon which a web application is built -- nor should they have to -- but they should certainly understand the fundamentals of human behaviour. If not, clicking on every link and every popup is certain to teach them a thing or two, fairly quickly.
Also, how is this Facebook's problem? They provide the medium, but they can't be responsible for the message it delivers, or they'd be actively censoring everything everyone does on their site. Have you seen some of the drivel these sites deliver? Can you imagine being one of the operators charged with keeping it all in line? I can't. I'd go mad. Or, rather, I'd go mad if I were policing today's level of FB content -- if FB were censored, I doubt it would ever have become this popular.
