Twitter-owned Vine’s videos autoplay in users’ timelines, unless you turn off autoplay in your settings – so it’s pretty hard to avoid them unless you’ve made a real effort to. Twitter just got in a bit of trouble over some of these Vine videos that featured flashing lights and colors.

Why?

Because they could have triggered seizures.

Epilepsy awareness group Epilepsy Action took issue with a couple of Vines advertising Twitter’s #DiscoverMusic posted by TwitterUK. According tot he group, the ads were “massively dangerous to people with photosensitive epilepsy.”

.@TwitterUK Your #DiscoverMusic Vines are massively dangerous to people with photosensitive epilepsy. Please take them offline now.

— Epilepsy Action (@epilepsyaction) July 10, 2015

It didn’t take Twitter long to realize its mistake and pull the ads.

“Eighty seven people are diagnosed with epilepsy every day and that first seizure can often come out of nowhere,” said Epilepsy Action’s deputy chief executive Simon Wigglesworth. “For a huge corporation like Twitter to take that risk was irresponsible.”

Irresponsible, of course. But did you know that Twitter was also running afoul of the UK’s main advertising authority?

From the BBC:

The Advertising Standards Authority told the BBC that “marketing communications”, even those uploaded on a company’s own website, should not include “visual effects or techniques that are likely to adversely affect members of the public with photosensitive epilepsy”.

 

It said both online and broadcast adverts in the UK had to adhere to rules made by the Committees of Advertising Practice.

 

“We take very seriously ads in online media that might cause harm to people with photosensitive epilepsy,” an ASA spokeswoman told the BBC.

The videos were up for about 18 hours.