Greasemonkey script to warn me when I open social-media sites

antisocial.user.js

// ==UserScript==
// @name     Avoid social media
// @version  1
// @grant    none
// @include   *://facebook.com*
// @include   *://*.facebook.com*
// @include   *://twitter.com*
// @include   *://*.twitter.com*
// @run-at  document-start
// ==/UserScript==

function removeContent() {
    var content = document.body;
    content.remove(); 
}

function warn() {
    var choice = confirm("Whoa, tiger. Is there something better you can do with the next few precious minutes? Get up and walk around the room.");
    if (choice == true) {

        alert("Good for you! Close the tab and get out of there.");
        window.stop();
        removeContent();

    } else {
        
        alert('Okay. Be careful out there.');
        hideFeeds();
        return;

    }
}

function hideFeeds() {
    var custom_css = '[id^="topnews_main_stream"],#sideNav,.home_right_column {display: none;}';
    var isFacebook = document.querySelector('html[id="facebook"]');
    if (isFacebook != undefined) {
        console.log('Eek! Facebook!');
        alert('Hiding your Facebook home feed for your own good. Anything important will be in your notifications.');
        var style = document.createElement('style');
        style.type = 'text/css';
        style.innerHTML = custom_css;
        document.getElementsByTagName('head')[0].appendChild(style);
    }
    var isTwitter = document.querySelector('link[href^="https://twitter.com"]');
    if (isTwitter != undefined) {
        console.log('Eek! Twitter!');
    }
}

//-- Don't run on frames or iframes
if (window.top != window.self) {
    return;
}

warn();

To do: https://twitter.com/alexia/status/947469905669926912 :)