Four times animations caused harm

I spend a lot of time talking about the Web Content Accessibility Guidelines (WCAG). Most guidelines concern making content work for disabled users, which is important. Disabled users must have access to the same services as everyone else. It's a civil rights issue.

A few criteria are a bit different, though. These concern not causing harm to users. It can feel a little unintuitive, that a website might cause physical harm to users, but it can happen. One excellent example is photosensitive epilepsy.

What is photosensitive epilepsy?

Epilepsy is a brain-related medical condition. It causes people to have seizures. Seizures come in many varieties, too many to go into here. When a seizure starts, the person with epilepsy may:

• be unconscious or otherwise unaware of their surroundings
• start jerking or shaking
• fall to the floor as their body becomes stiff or floppy

Seizures are usually short (seconds to minutes) and end on their own. A seizure that doesn't end within five minutes is usually a medical emergency.

People with epilepsy often take anti-seizure medications. They aim to avoid seizures where possible, as seizures are unpleasant and come with a risk of injury.

I'm not an expert on epilepsy, for deeper "what is epilepsy" content see:

• "What is epilepsy?" from Epilepsy Action, a UK non-profit. This focuses more on the experiences people with epilepsy have.
• "Explaining epilepsy" from the Mayo Clinic, a US healthcare organization. This focuses more on the diagnostic process and treatment approaches.

The rest of this post will be about photosensitive epilepsy. That's epilepsy caused by flashing or flickering lights. This affects about 3% of people with epilepsy.

This means these people are at risk of seizures, like the ones described above, if they're exposed to:

• Lights that flash more than about 3 times per second
• Animated GIFs or videos
• The glare, or shadow, caused by something rotating, like spinning fan blades
• A web page with certain patterns present. It's sometimes possible to simulate flashing by scrolling even if the patterns are still

What does WCAG say?

WCAG requires us to avoid things that flash more than three times per second, with a few limitations. Check the web page Understanding WCAG 2.3.1 (Level A) for a more precise description of the requirements.

Like all WCAG criteria, this is a floor, not a ceiling. This should make content safe for most users, but it doesn't offer any guarantees. For example, this permits content to flash if there isn't much difference between the lightnesses of the two colors. This might be safe for most people, but could become dangerous if the colors have been overridden.

In addition to this requirement, there is a more stringent, AAA-level criterion. This requires that nothing flashes more than three times, with no exceptions. As a AAA-level criterion, this isn't a legal requirement anywhere, at the time of writing. Check Understanding WCAG 2.3.3 (Level AAA) for more details.

Also, note that the term photosensitivity can appear in descriptions of other conditions, too. It's commonly used to describe certain types of migraine, and sometimes used in connection with autistic sensory issues. In these cases, exactly what causes issues might be different, but avoiding flashing content is a good start.

What happens when this goes wrong?

I recently needed to dig into the requirements and the history. I discovered stories about big organizations and people causing harm this way. Sometimes this seems careless, others are malicious.

Pokemon - 1997

One of the earliest widespread incidents relates to Pokemon (the TV series). An article from the New York Times (paywalled), published the following day, captures the story:

One moment they were happily munching on their dinner and watching their favorite cartoon show on television. The next moment, hundreds of children across the country were shaking and convulsing and being rushed to hospitals.

The full range of possible symptoms, beyond seizures, is on display too:

Victims said they got headaches or felt nauseated. Others said they felt groggy or carsick. Some victims recovered within an hour, while others were put in intensive care

This is, of course, a shocking story. The show was suspended for months following the incident and broadcasters added safeguards.

It seems as though nobody was expecting this kind of reaction.

Later, the incident has been the subject of parody. The Simpsons, season 10, episode 23, includes the Japanese cartoon "Battling Seizure Robots" (YouTube link).

London 2012 - 2007

In 2007, organizers of the Olympic and Paralympic games in London revealed the logo. While a lot of people didn't like it, another story made the headlines, too. An animation released to mark the launch could cause seizures.

A BBC News article noted that:

Charity Epilepsy Action said it had received calls from people who had suffered fits after seeing it.

The article also introduces the work of the late neuroscientist Professor Graham Harding. The Harding test detects whether content is likely to trigger a reaction. Using the test should be a prerequisite to material being broadcast, at least in the UK.

Kurt Eichenwald - 2016

The political climate in the United States has been troubling for the last decade. One incident that stuck in my memory concerns Kurt Eichenwald. Eichenwald is a journalist, who has written several books critical of Donald Trump.

Eichenwald also has epilepsy. He wrote a long piece in the New York Times Magazine, in 1987 detailing his experiences (paywalled). He talks about the impact the diagnosis had on his daily life. There's a lot of interesting details, especially about public perceptions in the 1980s.

In 2016, after the election, Eichenwald was critical of Donald Trump. In response, he received an animated GIF, on Twitter. The sender chose the GIF, with a strobing effect, in the hope that it would trigger a seizure. The sender, who was later identified as a 29 year-old from Maryland, wrote:

You deserve a seizure for your posts

Around the same time, he wrote to another person:

Spammed this at Eichenwald, let's see if he dies

The GIF did cause a seizure which, according to prosecutors, could have killed Eichenwald.

At the time, the story made a big impact, especially in technology news. Lawyers argued, successfully, that the GIF should be treated as a "deadly weapon".

December 2019, prosecutors announced that the sender intended to plead guilty. At the time of writing, I've not been able to find details of a sentence anywhere.

In September 2020, in a civil case, the sender agreed to pay Eichelwald $100,000 to settle out-of-court.

Predictably, the issue of whether a GIF should be classed as a weapon dominated news coverage. The deeper story here was a politically-motivated violent act, targeted using a disability. Eichenwald has spoken openly about epilepsy, which dictated the choice of attack.

This highlights, to me, that everywhere we allow users to upload media carries a risk. It's not enough to test your own content, you need to consider where users can display their own.

Epilepsy Foundation - 2019

In late 2019, the Eichenwald case was still making headlines. At this point, the Epilepsy Foundation, a US non-profit, started posting similar GIFs. "Hackers" had taken over their Twitter account.

In the first week of November, the foundation said there were 30 such posts made. In a Time magazine article, the foundation said it has filed a criminal complaint.

Usually, if someone takes over a social media account, it's for some kind of personal gain. Cryptocurrency pump-and-dump schemes and phishing seem the most common methods. What happened here, though, didn't enrich anyone. It only caused harm. Harm against people with epilepsy, for the sake of harm.

As someone from the foundation told the New York Times (paywalled):

These attacks are no different than a person carrying a strobe light into a convention of people with epilepsy and seizures, with the intention of inducing seizures and thereby causing significant harm to the participants

This goes beyond trolling. This is targeted violence against a subset of disabled people. It is delivered in a way to ensure it affects as many as possible.

The internet can be a depressing, frustrating place sometimes. Don't forget to ensure that your content doesn't cause harm to users and that you don't enable users to cause this type of harm to each other.