In 2008 Internet griefers attacked an online epilepsy support forum by posting code and flashing computer animation on the website to trigger seizures!
There is not one social forum with a comment option that does not draw them out to air their grievances, or to just spew forth hate, prejudices or general negative opinions.
On March 28, 2008, what seemed to have been a propaganda war between a group known as Anonymous (filled, of course, with anonymous users) and the Church of Scientology, turned really ugly when an online epilepsy support forum, run by the Epilepsy Foundation of America, was assaulted.
Reportedly the United Kingdom-based National Society for Epilepsy was also subjected to an identical attack, although this has not been confirmed.
Anonymous denied responsibility and blamed the Church of Scientology, saying the Scientologists did it "to ruin public opinion of Anonymous." Scientologist Tommy Davis accused Anonymous of hacking into the website.
The FBI could not find any evidence to link Anonymous to the incident and had "no reason to believe that these charges will be leveled against this group."
Members of the forum said they found a thread at 7chan.org (a supposed stronghold of Anonymous) in which the attack was being planned, but that thread has since been deleted.