Anonymous griefers induce epileptic seizures using JavaScript

I am not an easily shockable person. Anyone who knows me, anyone who has seen me, will understand this. Indeed, other than the usual trio of sexual or racial abuse and mindless violence it takes a lot to drop my jaw in shame and despair while browsing the web. However, a bunch of numbnut griefers managed to achieve just that over the weekend when they used a combination of JavaScript coding and flashing animations with the intent to trigger fits amongst the users of an epilepsy support website.