The Epilepsy Foundation's quick reaction to a recent attack on one of its online forums raises awareness of the need for Web security for some health organizations. On Easter weekend, the Epilepsy Foundation -- and those who use its online forums for help, support, suggestions and camaraderie -- came under attack by people who posted rapidly flashing images to cause serious injury and harm.

Barrages of messages are oftentimes problematic for electronic venues, but nothing more than a nuisance, or a potential embarrassment if pornographic images are included in the attacks. But for people with epilepsy, rapidly flashing text or images can cause actual harm to the person viewing the material, because such flashing or flickering objects can bring on seizures, or seizure-like activity. The type of epilepsy that causes people to experience seizures upon seeing flashing or flickering images is photosensitive epilepsy. In fact, many people who viewed the at-first harmless-looking messages recently posted on the Foundation's forums involuntarily froze when they saw what was posted, even if they didn't experience a full-on seizure.

"This was clearly an act of vandalism with the intent to harm people, and we shut the attack down immediately," said Eric R. Hargis, president and CEO of the Epilepsy Foundation. "We've established deterrents in the system to prevent similar incidences."

The Epilepsy Foundation has been on the forefront of efforts to prevent this type of seizure. Three years ago the organization assembled a group of experts on photic- and pattern-induced seizures and released its recommendations for preventing seizures provoked by dynamic light and imaging sources such as television, videogames, websites, motion pictures and other media. The consensus recommendations covered factors, such as light intensity, flicker, contrast, duration and pattern, and the technical parameters within these factors that are most likely to provoke seizures in susceptible individuals.

More than 3 million Americans have epilepsy (approximately one in every 100); while about 3 percent of those people have photosensitive epilepsy.

Photosensitive epilepsy has been in the news increasingly over the last few years. A logo animation for the 2012 Olympics in Britain caused thousands of people to experience seizures last summer. In 1997 an episode of an animated TV series caused thousands of children to experience seizures in Japan. Some video games have also caused seizures. Such warnings are included on most -- if not all -- video games today as a result. Though the Japanese government established guidelines following the incidences in that country, the Epilepsy Foundation's Seizures and Photosensitivity guidelines are the only such recommendations in the United States.