>>509291348 (OP)There definitely are videos out there. But I do think the amount is disproportionate to the statistics.
My personal take would be a combination of these factors
1.) As others have mentioned, it's not easy to rape people. As a result I imagine an attacker would have a tough time holding a cellphone or handheld camera in any way that it would capture usable footage while trying to subdue a struggling victim
2.) While there are millions of rapes a large portion likely occur within primitive villages in India, Africa, etc that may not have widespread ownership of cellphones and internet access.
Combining these two factors reduces the chance for a successful rape to be caught on camera with any amount of clarity by a considerable amount. After that the perpetrator would still need to go out of his way to upload it to the internet, incriminating himself in the process. Most porn sites remove such material very quickly, so he would have to upload it to some shitty unknown site with lax moderation, further reducing the probability of someone being able to find it through traditional methods like search engines, etc.