I think "they're welcome to try" is exactly the right response here. Nothing is "fair" or "unfair", at least not in a way that advertisers or ad blockers care about.
No matter what they do it's entirely possible to trick their scripts into believing I'm displaying ads, because they run not on facebook's servers but on my computer. Where I get the control.
DRM-protected media extensions are almost uniquely positioned for this. They're designed around the abilities to uniquely identify the user and resist tampering. The only thing that's missing right now is interactivity.
I think you're completely right, btw. After AOL, it only took a few years for websites to become rapidly Flash-based. It looks like we're going back to that again (not Flash, but same thing - black boxed).
I hope this is true. I still think Facebook can do much more devious things like having posts on your news feeds from friends which look like posts but are ads. Kind of like native advertising.