Something-Awful-No-External-Ads.user.js

// ==UserScript==
// @name         Something Awful No External Ads
// @version      0.1.0
// @description  Hide ads when they lead off site
// @updateURL    https://gist.githubusercontent.com/Chunjee/4df598ae748afecd40ca7d22732b8756/raw/%2520Something-Awful-No-External-Ads.user.js
// @match        *://forums.somethingawful.com/*
// @namespace    http://github.com/Chunjee
// @author       Chunjee
// ==/UserScript==


$(document).ready((function() {
    //grab the bottom banner
    var banner_obj = $("#ad_banner_user");
    //check if ad link leads to SA
    var ad_link = /:\/\/(forums\.somethingawful\.com)\/showthread/gi.exec(banner_obj[0].innerHTML);
    //if ad link was anything else than SA, hide it.
    if (!ad_link) {
        $("#ad_banner_user").hide();
    }
}));

readme.md

Sorry Aggro Gator