Browsers should have an option to follow one of four behaviors: a) allow all P2P connections, b) always ask, c) allow a low-volume (say, <32kbps) P2P traffic, but throttle and ask if the rate tries to go beyond the safe threshold and d) deny all P2P connections. With b) or c) being a sane default, and a JS API to check permissions programmatically.
While this doesn't solve the problem right now (and would probably take a long while to happen), as a long-term solution, I think that would be the best way for everyone, providers and consumers.
I just think if you'll raise an issue with the mainstream vendors (Mozilla, Google, Opera, Vivaldi) you (as a company) this idea may have slightly better chances to be heard than just some random end-user suggestions.
If this idea fits your vision, of course.
As a short term, I guess maybe you can implement some proprietary API and suggest your users (webmasters) to show a confirmation panel that fits their site look-and-feel. With some readily-available sample implementation that they can just use if they don't want to spend time at all (besides adding a line of code).