[Oblivious]

What is WebRTC?
WebRTC is an open framework for the web that enables Real Time Communications in the browser. It includes the fundamental building blocks for high-quality communications on the web, such as network, audio and video components used in voice and video chat applications.
These components, when implemented in a browser, can be accessed through a JavaScript API, enabling developers to easily implement their own RTC web app.
The WebRTC effort is being standardized on an API level at the W3C and at the protocol level at the IETF.

This is a crucial because even with a VPN your IP is still visable.
on Firefox type in about:config, change these settings:
  media.peerconnection.enabled = false
   media.peerconnection.turn.disable = true
   media.peerconnection.use_document_iceservers = false
   media.peerconnection.video.enabled = false
   media.peerconnection.identity.timeout = 1

to test if you are vulnerable to the WebRTC leak head over to this site
https://browserleaks.com/webrtc#webrtc-device-id

for Chrome:
    WebRTC in Google Chrome and Chromium-based web browsers is supported and enabled by default since Chrome version 23.
   To protect IP addresses from leaking, using the official webrtc.org extension WebRTC Network Limiter. It has few options, depending on what you're looking     for.