If you frequent epilepsy forums on the internet - beware! Some of these sites have been afflicted by hackers that post bright, flashing lights and colors that are known to trigger seizures in some individuals when they open up the forum posts. Known as photosensitive epilepsy, these images can trigger violent seizures in this group of individuals. The Epilepsy Foundation was also affected by these hackers and has taken the images down. You can read more about the problem and their steps to correct it here.