dontfwithpaste.user.js

// ==UserScript==
// @name         Don't F With Paste
// @description  Stop idiots who think they're clever
// @downloadURL  https://gist.github.com/emlyn/e8a626ad794d36eb0856655c32bcf955/raw/dontfwithpaste.user.js
// @updateURL    https://gist.github.com/emlyn/e8a626ad794d36eb0856655c32bcf955/raw/dontfwithpaste.user.js
// @namespace    https://gist.github.com/emlyn
// @version      0.3
// @author       Emlyn Corrin
// @match        http*://*/*
// @exclude      http*://docs.google.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    const allowPaste = function(ev) {
        ev.stopImmediatePropagation();
        return true;
    };

    document.addEventListener('paste', allowPaste, true);
})();