Remove about: chrome: and resource: URIs from the src attribute of <img> tags.
// ==UserScript==
// @name Block internal images hardcoded in IMG tag
// @description Remove about: chrome: and resource: URIs from the src attribute of <img> tags.
// @author Jefferson "jscher2000" Scher
// @namespace JeffersonScher
// @copyright Copyright 2016 Jefferson Scher
// @license BSD 3-clause
// @include http*://*
// @version 0.5.1
// @grant none
// ==/UserScript==
// Inspiration -- also deals with <script> tags: http://userscripts-mirror.org/scripts/review/5899
// Check <img> tags for about: chrome: resource: URLs
var problemimgs = document.querySelectorAll('img[src^="about:"], img[src^="chrome:"], img[src^="resource:"]');
for(var i = 0; i < problemimgs.length; i++){
if (problemimgs[i].hasAttribute("onload")) problemimgs[i].removeAttribute("onload");
if (problemimgs[i].hasAttribute("onerror")) problemimgs[i].removeAttribute("onerror");
problemimgs[i].setAttribute("alt", "BLOCKED: "+problemimgs[i].getAttribute("src"));
problemimgs[i].removeAttribute("src");
problemimgs[i].setAttribute("style", "border:3px double red; color:red; font-weight:bold; font-style:italic; padding: 1px 4px;");
}