Social media wasn't designed for this: Twitter trolls maliciously targeted people with epilepsy - attempting to induce seizures.
The Epilepsy Foundation says flashing and strobing GIFs and videos were posted in November, incorporating the US charity's own Twitter handle and hashtag.
The attacks came during national epilepsy awareness month.
Allison Nichol, the foundation's legal advocacy director says they're working with law enforcement to bring the perpetrators to justice - telling the BBC that the attackers were intent on "inducing seizures and thereby causing significant harm to the participants."