Maybe it is just my warped perspective, but when I looked at the technology this all came to mind immediately, but I just as immediately dismissed it because of the "hosted proxy service": the fee was seemingly "too low".
So, I feel like you've left out the key non-obvious part: it turns out that even if you do the brain-dead un-optimized "let's use Amazon EC2" for your proxies, $30/yr at $0.05c/GB (down: up is free) buys 50GB/mo.
Given that the user is then going to be filing this data over their 3G connections, 50GB/mo is (based on reports of users tethering that complain about rate limiting and caps) at the very high-end of usage.
So, with that aside, the rest of this actually boils down to: "the webpage just makes two outgoing websocket connections; one to a proxy, and the other to an app on the PC, itself providing a custom network driver".
So, I feel like you've left out the key non-obvious part: it turns out that even if you do the brain-dead un-optimized "let's use Amazon EC2" for your proxies, $30/yr at $0.05c/GB (down: up is free) buys 50GB/mo.
Given that the user is then going to be filing this data over their 3G connections, 50GB/mo is (based on reports of users tethering that complain about rate limiting and caps) at the very high-end of usage.
So, with that aside, the rest of this actually boils down to: "the webpage just makes two outgoing websocket connections; one to a proxy, and the other to an app on the PC, itself providing a custom network driver".