[MichaelGG]

Downloading isn't a concern, as websites can already force you to download a file. <img src=...> The new risk is P2P connections that bypass HTTP settings, and perhaps uploading. (You could already upload by making a POST, so it's only in combination with P2P stuff that this is novel.)

If WebRTC prompted or forced use of the HTTP connection settings in the browser, I'd have no issue with it.

[jacquesm]

That's true but this combination allows for first downloading then serving up illegal content to many consumers and the penalties for that are much harsher. A post would go to one place only (normally speaking) and would not suddenly allow your browser to become server, making you a point of distribution.

[alkonaut]

So instead of "Someone else did it on my WiFi", people will now say "I didn't transfer those files, a webpage did it without my knowledge". Sounds like a much more solid excuse actually.