Epilepsy charity criticises Twitter for flashing ads
Twitter has responded to an epilepsy charity that said two of its online adverts were "irresponsible".
The social media giant had uploaded two short videos on Vine that featured a looping, rapid succession of flashing colours.
"Twitter's ads were dangerous to people living with photo-sensitive epilepsy," said Epilepsy Action's deputy chief executive, Simon Wigglesworth.
Twitter told the BBC it had removed the videos on Friday morning.
Around one in 3,500 people in the UK has photosensitive epilepsy, according to Epilepsy Action. Seizures can be triggered by flashing lights and bold patterns.
An episode of Japanese cartoon Pokemon was famously blamed for triggering convulsions in 1997.
"Eighty seven people are diagnosed with epilepsy every day and that first seizure can often come out of nowhere," said Mr Wigglesworth.
"For a huge corporation like Twitter to take that risk was irresponsible."
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.
Twitter's flashing Vine videos were online for 18 hours before the company removed them.
Epilepsy Action said it was "pleased" that Twitter had replied to its messages and removed the posts.
Rachel Bremer, Twitter's international communications director, thanked the charity for highlighting the issue.
"We appreciate your feedback," she said on Twitter.