I know that a number of forums and other sites restrict, or do not permit, some types of animated gifs. While most such gifs are harmless some may cause a reaction in many viewers that is similar to motion sickness. The most problematical animated gifs seem to be those with a "swirling" motion rather than a "rectilinear" motion.
To anyone who may not understand this optical-mental problem, have you ever looked out a car window in winter watching snow coming down? Well, that leaves out anyone below the Mason-Dixon line. Anyway, it can have a sort of ticklish effect on the brain. I have experienced this myself from watching snow coming down.
Some people are what is called photo-sensitive and flashing lights, etc, may trigger an epileptic attack. A couple years ago Twitter was subjected to an attack targeting the Epilepsy Foundation with animated gifs designed to trigger an epileptic attack in sensitive people, and they certainly discomfited others. See https://www.theverge.com/2019/12/23/21035855/twitter-bans-apngs-trolls-seizures-epilepsy-foundation-....
The same Verge article refers to a famous case from a couple years ago where the FBI arrested someone for sending an animated gif to a journalist who then had an epileptic attack. The perpetrator knew of the journalist's condition and purposely sent him the animated gif as an attack.
I have seen the use of some animated gifs in the AARP forums for some time and I try to avoid looking at them as they can trigger vertigo due to my Meniere's disease. I've sometimes thought I might mention this to AARP but have not until now. I am certain that there must be many readers who also are sensitive to such animated gifs.
I would like to recommend to AARP that animated gifs be restricted or banned. In my view some of the uses here in this forum have been knowingly deployed for the purpose of such attacks rather than for the "coolness" effect. JMO.
