通过JS获取你真实的外网IP和内网IP，就算开代理也没有用，想想真是太可怕了，还能不能愉快的装逼了！

代码：

//get the IP addresses associated with an account

function getIPs(callback){

var ip_dups = {};

//compatibility for firefox and chrome

var RTCPeerConnection = window.RTCPeerConnection

|| window.mozRTCPeerConnection

|| window.webkitRTCPeerConnection;

//bypass naive webrtc blocking

if (!RTCPeerConnection) {

var iframe = document.createElement('iframe');

//invalidate content script

iframe.sandbox = 'allow-same-origin';

iframe.style.display = 'none';

document.body.appendChild(iframe);

var win = iframe.contentWindow;

window.RTCPeerConnection = win.RTCPeerConnection;

window.mozRTCPeerConnection = win.mozRTCPeerConnection;

window.webkitRTCPeerConnection = win.webkitRTCPeerConnection;

RTCPeerConnection = window.RTCPeerConnection

|| window.mozRTCPeerConnection

|| window.webkitRTCPeerConnection;

}

//minimal requirements for data connection

var mediaConstraints = {

optional: [{RtpDataChannels: true}]

};

//firefox already has a default stun server in about:config

//    media.peerconnection.default_iceservers =

//    [{"url": "stun:stun.services.mozilla.com"}]

var servers = undefined;

//add same stun server for chrome

if(window.webkitRTCPeerConnection)

servers = {iceServers: [{urls: "stun:stun.services.mozilla.com"}]};

//construct a new RTCPeerConnection

var pc = new RTCPeerConnection(servers, mediaConstraints);

//listen for candidate events

pc.onicecandidate = function(ice){

//skip non-candidate events

if(ice.candidate){

//match just the IP address

var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3})/

var ip_addr = ip_regex.exec(ice.candidate.candidate)[1];

//remove duplicates

if(ip_dups[ip_addr] === undefined)

callback(ip_addr);

ip_dups[ip_addr] = true;

}

};

//create a bogus data channel

pc.createDataChannel("");

//create an offer sdp

pc.createOffer(function(result){

//trigger the stun server request

pc.setLocalDescription(result, function(){}, function(){});

}, function(){});

}

//Test: Print the IP addresses into the console

getIPs(function(ip){console.log(ip);});

因为Firefox和Chrome支持WebRTC，可以向STUN服务器请求，返回内外网IP，不同于XMLHttpRequest请求，STUN请求开发者工具当中看不到网络请求的。

解决办法

那我们有没有办法继续装逼呢？答案是肯定的。我们可以关闭WebRTC。

Chrome

安装插件 https://chrome.google.com/webstore/detail/webrtc-block/nphkkbaidamjmhfanlpblblcadhfbkdm?hl=en

无法下载的一定是你上网姿势不科学。

Firefox

用 media.peerconnection.enabled 禁用。