. . . so turn it off? I mean, someone could hack your computer and (effectively) do the same thing for the couple of minutes it takes you to figure out what's happening and flip the power switch. It's a screen. They're all screens.
The real danger is from more subtle manipulation, assuming most people come to trust what's being displayed. That's true of any information source that can be spoofed, though. GPS errors are bad enough already.
His point was that turning it off is not an option: The automated porn-feed injected into your glasses/contacts/etc could make it offensive enough to effectively deny service.
Even if not porn, Spam WILL be targeted at these eventually. I recall a scene in either "The Diamond Age" or perhaps a Gibson novel where the characters were using smart chopsticks that had been hit by malware which had once spewed ads but in that particular are of town had been spewing porn. Onto chopsticks.
(With my luck, it was Rainbow's End that had this scene -- I forget where I saw it, but it was memorable.)
There will always be someone trying to find a way to inject ads.
In my (admittedly limited) experience people don't weld contacts to their eyes, nor are contacts capable of physically restraining you from pushing an 'Off' button. I suppose you could attack someone with epilepsy this way.
The rest of your post is rather more accurate. Hence the need for good security (on devices that you don't wear as well as ones that you do).
The real danger is from more subtle manipulation, assuming most people come to trust what's being displayed. That's true of any information source that can be spoofed, though. GPS errors are bad enough already.