Internet Paraphilia usually refers to the unusual fetishes pertaining by a certain group of the internet community. Often related to furries (known as “furry fetish”) and deviantART users due to the substantial amount of arts relating to the fetishes in their respective sites, these paraphilia can be found in many forms, and among the most common are transformation, foot fetish, inflation, vore, pregnancy, etc. Other forms of internet paraphilia can be transgenderism, micro/macro, muscle fetish, suiting fetish, mind control, tickle, diapers and many others. Due to the fetishistic nature of the paraphilia, they are often considered NSFW.
Origins
It’s not clear when the first of such fetishes start appearing in the internet, but by around 2006, such fetishes and paraphilia has become a common sight in sites such as FurAffinity or deviantART.
Spread
Like what “Origins” say, it’s difficult to determine how fast is the spread of the Internet Paraphilia and when was its peak of its spread. But a simple search in sites like deviantART and FurAffinity with generic topics like Pokemon or any anthro creatures will often yield such results. In 4chan, these fetishes are often ridiculed as mentioned in many Encyclopedia Dramatica articles since around 2007 or 2008.