Main road to expose one’s identity is checking the device’s IP Address. It can be requested several ways. If you want 100% anonymity you will have to spoof this as well. So you will have to connect thru VPN or Proxy to actually change it.
Simply spoofing WebRTC won’t be enough, you will have to connect to some SOCKS.
For the best result follow our article about how to get 100% anonymity.