What if a lot of people did that?
Suddenly Facebook's cost for hanging onto all these videos would become quite high with no value in doing so.
Anyone feel like making a website to help automate that process?
I feel the effort you and countless opt-in people would expend could be redirected to much more fruitful efforts. Convincing people to delete their profiles, for example.
However, if you wanted to do this, why bother recording it? Read a little about the mp4 spec and it would probably be fairly easy to generate mp4s containing random data. You could even go further and generate video that tricks facial/object recognition.
There are general-strike level attack surfaces on these networks, but people don't really care that much.
Lockout would be worse than account deletion. You would have no recourse to fight back on any of their use of your data right?
Yes you would if you were European. You can't stop people exercising their legal rights because they broke your terms of service.
That is exactly what a lot of people do. I don't think Facebook is conspiratorially hording funny cat videos. It's just standard practice to flag things as deleted. Everyone does it. I certainly have.