I mostly encounter them on reddit and it seems they just happen to use gifv. Just skimming through the first few pages and it looks like all of the videos are

I mostly encounter them on reddit and it seems they just happen to use gifv. Just skimming through the first few pages and it looks like all of the videos are gifv: NSFW https://old.reddit.com/domain/imgur.com/ https://old.reddit.com/domain/imgur.com/