The headache effect some people got from it was very real, however. At least if I am correct, if the idiots who made the videos stuck a 19Hz or so sine wave in the background, if someone were to listen to it with decent headphones or with a VERY loud surround setup, the frequency will cause the eyes to vibrate very slightly which can cause headaches, nausea, mild out-of-focus hallucinations and pressure behind the eyes. It wouldn't be hard to stick a frequency like this in there without people noticing, the fact that not everybody got a headache/felt wierd after watching it would probably be because not everybody listened to it with headphones, not neccessarily the placebo effect (though I'm sure that had a factor in it).
However it was still pretty obvious it was a fake, if they wanted to make it look like a real TV hijacking, they could've at least shown the programming before and after the hijacking, thrown in some interference and made the fonts a lil more blurry -_- Compare those videos to a
real TV hijacking.
EDIT: You can try the 19Hz thing in Soundforge or whatever, generate a 19Hz sine wave about a minute long, put on some loud headphones with good bass response and see what happens. I tried it and almost immediately it felt like my whole body was vibrating, and no pleasantly, it was REALLY uncomfortable and made the back of my eyes ache. You must have headphones for this to work in order for the desired effect (eye vibration) to happen, as well as be of a sufficient volume. Be careful not to turn the volume up too high though, or you'll break your headphones and if not, your eardrums -_-