It would be negligent of me not to mention this, so here goes...

If you use a webtorrent service (such as #peertube), the default behaviour is to share "stuff" from your hard drive back to the web, bypassing firewalls and VPNs over WebRTC.

The claim is that webtorrent will only share things and fragments of things you download, but you need to be aware of this, and be alert because I haven't studied the security model closely and don't know if it can be bypassed. Even if it only shares things you downloaded via the same mechanism, it becomes public knowledge that your IP accessed a certain file.

I just remember trying Napster some years ago and found (to my horror) that the entire contents of my hard drive were being shared with the internet, without asking me, and through a firewall. I uninstalled it quickly.

In recent peertube releases this behaviour can apparently be turned off, but 'on' is the default condition and applies if you merely visit a peertube site and watch videos. I would recommend for Zap (etc.) folks to only watch these videos through the link we provide on your own site (which is an mpeg and doesn't involve WebRTC and webtorrent).