[cpeterso]

You can test WebRTC IP address (and media device id) leakage using https://browserleaks.com/webrtc.

To disable WebRTC in Firefox, set the about:config prefs "media.peerconnection.enabled" and "media.navigator.enabled" to false.

[anfilt]

More like this:

    media.peerconnection.turn.disable = true
    media.peerconnection.use_document_iceservers = false
    media.peerconnection.video.enabled = false
    media.peerconnection.video.vp9_enabled = false
    media.peerconnection.video.h264_enabled = false
    media.peerconnection.identity.enabled = false
    media.peerconnection.identity.timeout = 1

[ta34662211]

I need to find a way to automate the patching of Firefox's about:config when installing a new OS etc, quite a few telemetry/storage/WebRTC tweaks to date now.

There is an extension [1] that'll at least disable the IP address gathering (it doesn't look to disable all of the above settings but may have a similar effect if browser.privacy.network.peerConnectionEnabled disables everything):

[1] https://github.com/ChrisAntaki/disable-webrtc-firefox

[anfilt]

The simplest level would to add what settings you want to Prefs.js file. http://kb.mozillazine.org/Prefs.js_file

If you want the preferences locked the application level and not be overridden or be unchangeable at profile level. Mainly important if you are managing a lot systems. http://kb.mozillazine.org/Locking_preferences

[UnrealIncident]

Look into vendor.js for patching about:config. I know Arch has one for sure in their package.