alt Hacker NewsFree VPN's are usually funded by agreeing to route some VPN traffic for other people though your own network. They basically work as mixers, randomizing traffic throughout the VPN population.
This can expose users to legal risks, but but can also add plausible deniability at the same time "it wasn't me, it was someone on VPN".
I’ve suspected that’s where these “ethical” (as they like to call it) residential proxy services get their access from. They’re really dodgy about it other than saying the people agree to it, which ya ok.