If you're a computer owner, you know the harm that hackers can do. They can break through a firewall and steal sensitive data, turn your PC into a spam zombie, causing it to send out millions of unwanted letters, or they can try to deliberately infect your machine with a virus.
But up until now, they've never done anything quite as terrible as this.
Some unknown online intruders recently hacked into the website run by the Epilepsy Foundation, a group that gives out information about the medical condition. Epileptics can experience seizures brought on by a number of factors, including bright, rapidly flashing lights, busy pictures, video games and even cartoons.
So in a mean spirited and potentially dangerous act, someone gained control of the site and posted hundreds of photos of rapidly flashing images, along with links to areas where similar slideshows would be repeated.
Those who innocently ventured to the site were guided to supposedly helpful information about the problem, the kind anyone diagnosed with epilepsy might be interested to see. But when they clicked one of those links, they were transported without warning to a page featuring a kaleidoscope of rapidly changing colour images - the kind that can bring on a seizure.
A number of visitors reported getting migraines and having near-seizures as a result of their visit, an outcome accomplished by exploiting a vulnerability in the group's publishing software that allowed the public to post their own images.
"They were out to create seizures," condemns the Foundation's Ken Lowenberg, who notes the feature has now been disabled.
The FBI is looking into this case since it put people's lives and health at risk. But so far, there's no sign of the culprit. What's so disturbing about the incident is how senseless it was. Unlike most hackers, nothing was done for profit, there was no 'cause' involved, the site's users weren't sent a virus and no one benefited in any way.
"I count this in the same category of teenagers who think it's funny to put a cat in a bag and throw it over a clothesline - they don't realize how cruel it is," relates Trend Micro security Paul Ferguson. "It was an opportunity waiting to happen for some mean-spirited kid."
It's not the first time people with a disability or a physical problem have been targeted online, although it appears to be the worst example on record. Earlier this year, hackers released code that disabled the machines used to read computer screens out loud for the blind. But authorities say in that case, the motive appeared to be stopping those who were using the software illegally.
This latest incident seems to have no such strings attached, with those in the know insisting it was just plain mean.
Photo credit: Jens Schlueter/AFP/Getty Images