Well, I'm not an expert, but the w3c Accesibility guidelines say:
"2.3.1 Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds."[0]
And also:
"Individuals who have photosensitive seizure disorders can have a seizure triggered by content that flashes at certain frequencies for more than a few flashes. People are even more sensitive to red flashing than to other colors, so a special test is provided for saturated red flashing."[1]
It is clear that this are only guidelines, not laws, but in this particular case I think it is appropriate to make some kind of warning for this users.
"2.3.1 Three Flashes or Below Threshold: Web pages do not contain anything that flashes more than three times in any one second period, or the flash is below the general flash and red flash thresholds."[0]
And also: "Individuals who have photosensitive seizure disorders can have a seizure triggered by content that flashes at certain frequencies for more than a few flashes. People are even more sensitive to red flashing than to other colors, so a special test is provided for saturated red flashing."[1]
It is clear that this are only guidelines, not laws, but in this particular case I think it is appropriate to make some kind of warning for this users.
[0]http://www.w3.org/TR/2008/REC-WCAG20-20081211/#seizure [1]http://www.w3.org/TR/UNDERSTANDING-WCAG20/seizure-does-not-v...