youtube censorship toolkit - blocks users, channels, topics,

// ==UserScript==
// @name        youtube censorship toolkit
// @namespace   censorship
// @version     1
// @grant       none
// @edited      10/1/2016
// ==/UserScript==

var users = [
  "user0",
  "user1",
  "user2"
];

var nUsers = users.length;

var channels = [
  "channel0",
  "channel1",
  "channel2"
];

var nChannels = channels.length;

var playLists = [
  "playList0",
  "playList1",
  "playList2"
]

var nPlayLists = playLists.length;

var displayUsers = false;

var displayChannels = false;

var displayPlayLists = false;

var displayComments = false;

var autoplay = false;

var block = function(elements){
  for(var i = 0, N = elements.length; i < N; ++i){
    var e = elements[i];
    if(e.style.display != "none"){
     var node = e.parentNode;
     while(node){
      if(node.tagName.toLowerCase() === "li") break;
      node = node.parentNode;
     }
     if(node){
      node.style.display = "none";
      e.style.display = "none";
     }
    }
  }
}

var blockByContent = function(expressions, nExpressions, elements){
  for(var i = 0, N = elements.length; i < N; ++i){
    var e = elements[i];
    var skip = true;
    for(var j = 0; j < nExpressions; ++j){
     if(expressions[j].test(e.innerHTML) === true){
       skip = false;
       break;
     }
    }
    if(skip) continue;
    if(e.style.display != "none"){
       var node = e.parentNode;
       while(node){
        if(node.tagName.toLowerCase() === "a") break;
        node = node.parentNode;
       }
       if(node){
        node.style.display = "none";
        e.style.display = "none";
       }
    }
  }
}

var queries = {};

queries.blockByUserName = {};
queries.blockByUserName.query = "";
queries.blockVideoWallByUserName = {};
queries.blockVideoWallByUserName.query = "";
queries.blockVideoWallByUserName.expressions = [];
queries.blockVideoWallByUserName.nExpressions = 0;
queries.blockByChannelName = {};
queries.blockByChannelName.query = "";
queries.blockByPlayListName = {};
queries.blockByPlayListName.query = "";

(function(){
  let blockByUserName = "";
  for(var i = 0, N = nUsers; i < N; ++i){
   if(i > 0){
    blockByUserName += ', ';
   }
   blockByUserName += "li a[href='/user/" + users[i] + "']";
   queries.blockVideoWallByUserName.expressions.push(new RegExp(users[i], "i"))
  }
  queries.blockByUserName.query = blockByUserName;
  queries.blockVideoWallByUserName.query = "a span[class*='ytp-videowall-still-info-author']";
  queries.blockVideoWallByUserName.nExpressions = queries.blockVideoWallByUserName.expressions.length;
})();

(function(){
  let blockByChannelName = "";
  for(var i = 0, N = nChannels; i < N; ++i){
   if(i > 0){
    blockByChannelName += ', ';
   }
   blockByChannelName += "li a[href='/channel/" + channels[i] + "']";
   blockByChannelName += ", li span[data-ytid='" + channels[i] + "']";
  }
  queries.blockByChannelName.query = blockByChannelName;
})();

(function(){
  let blockByPlayListName = "";
  for(var i = 0, N = nPlayLists; i < N; ++i){
   if(i > 0){
    blockByPlayListName += ', ';
   }
   blockByPlayListName += "li a[href='/playlist?list=" + playLists[i] + "']";
  }
  queries.blockByPlayListName.query = blockByPlayListName;
})();

var blockByUserName = function(){
  block(document.querySelectorAll(queries.blockByUserName.query));
  blockByContent(queries.blockVideoWallByUserName.expressions, queries.blockVideoWallByUserName.nExpressions, document.querySelectorAll(queries.blockVideoWallByUserName.query));
}

var blockByChannelName = function(){
  block(document.querySelectorAll(queries.blockByChannelName.query));
}

var blockByPlayListName = function(){
  block(document.querySelectorAll(queries.blockByPlayListName.query));
}

var blockComments = function(){
  var comments = document.getElementById("watch-discussion");
  if(comments){
    comments.style.display = 'none';
  }
}

var disableAutoplay = function(){
  var autoplay = document.getElementById("autoplay-checkbox");
  if(autoplay && autoplay.checked === true){
    autoplay.click();
  }
}

var execute = function(){
  if(!displayUsers) blockByUserName();
  if(!displayChannels) blockByChannelName();
  if(!displayPlayLists) blockByPlayListName();
  if(!displayComments) blockComments();
  if(!autoplay) disableAutoplay();
}

var observer = null;

if(document){
  observer = new MutationObserver(function(mutations){ execute(); });
  observer.observe(document.body, { childList: true, subtree: true });
}