Block HTML5 video.
// ==UserScript==
// @name [ALL] Block HTML5 Video
// @author
// @description Block HTML5 video.
// @downloadURL
// @grant
// @homepageURL https://bitbucket.org/INSMODSCUM/userscripts-scripts/src
// @icon
// @include http*://*
// @namespace insmodscum
// @require
// @run-at document-start
// @updateURL
// @version 1.0
// ==/UserScript==
(function(){
var script = document.createElement("script");
script.type = "text/javascript";
script.textContent = 'document.createElement("video").constructor.prototype.canPlayType = function(type){return ""}';
document.documentElement.appendChild(script);
})();