Google+ Post Censorship => Censor the words in your post.

gplus.censor.post.user.js

/*
    Google+ Post Censorship => Censor the words in your post.
    Copyright (C) 2012 Jingqin Lynn
    
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

// ==UserScript==
// @name 		Google+ Post Censorship
// @namespace		http://project.quietmusic.org/j/
// @description		Censor the words in your post.
// @match		https://plus.google.com/*
// ==/UserScript==

function doClick(target) {
	var e;
	e = document.createEvent("MouseEvents");
	e.initEvent("mousedown", true, true);
	target.dispatchEvent(e);
	e = document.createEvent("MouseEvents");
	e.initEvent("click", true, true);
	target.dispatchEvent(e);
	e = document.createEvent("MouseEvents");
	e.initEvent("mouseup", true, true);
	target.dispatchEvent(e);
	return target;
};

function doKeypress(target) {
	var e = document.createEvent("KeyboardEvent");
	e.initEvent("keypress", true, true, window, 0, 0, 0, 0, 0, "e".charCodeAt(0));
	target.dispatchEvent(e);
	return target;
};

var urlPrefix = "http://sopastrike.com/#?/censor/";
var censorChar = "█";
var censorCharCode = censorChar.charCodeAt(0);

var censorWord = function (len) {
	return Array(len + 1).join(censorChar);
}

var uncensorText = function(e) {
	if(!e) e = event;
	e.preventDefault();
	var span = e.target;
	span.parentElement.replaceChild(document.createTextNode(span.title), span);
};



var onCensorButtonClick = function (e) {
	if(!e) e = event;
	e.preventDefault();
	var sel = document.getSelection();
	if(sel.anchorNode == sel.focusNode && sel.anchorNode instanceof Text) {
		var start = sel.anchorOffset;
		var end = sel.focusOffset;
		if(start == end) return;
		if(start > end) {
			var t = start;
			start = end;
			end = t;
		}
		var txt = sel.anchorNode;
		var post = txt.textContent;
		
		var beforeText = document.createTextNode(post.substr(0, start));
		
		var span = document.createElement("span");
		span.textContent = censorWord(end - start);
		span.setAttribute("title", post.substring(start, end));
		span.setAttribute("contenteditable", "false");
		span.setAttribute("tabindex", "-1");
		span.setAttribute("censored", "true");
		span.addEventListener("contextmenu", uncensorText, false);
		
		var p = txt.parentElement;

		txt.nodeValue = post.substr(end);
		p.insertBefore(beforeText, txt);
		p.insertBefore(span, txt);
		
		if(!p.getAttribute("censored")) {
			p.setAttribute("censored", "true");
			
			var onShareButtonMousedown = function(e) {
				if(!e) e = event;
				e.preventDefault();
				e.target.removeEventListener("mousedown", onShareButtonMousedown, false);
				p.removeAttribute("censored");
				var spans = p.querySelectorAll("span[censored='true']");
				var uncensored = new Array();
				for(var i = 0; i < spans.length; i++) {
					uncensored.push(encodeURIComponent(spans[i].title));
				}
				var uri = urlPrefix + uncensored.join("/");
				addUncensoredLink(uri);
			};
			document.querySelector(".e-U-me-Qf").addEventListener("mousedown", onShareButtonMousedown, false);
		}
	}
};

var addUncensoredLink = function (uri) {
	var insertTo = document.querySelector(".k-Qf-e-fa");
	//This will fail for unknown reasons:
	//insertTo.addEventListener('DOMNodeInserted', onMediaInserted, false);
	doClick(document.querySelector(".e-ja-p.e-ja-p-C"));
	var intMedia = setInterval(function() {
		var urlBox = insertTo.querySelector(".Nf");
		if(urlBox) {
			clearInterval(intMedia);
			urlBox.value = uri;
			doKeypress(urlBox);
			var addButton = document.querySelector(".jhqR7");
			var i = setInterval(function() {
				if(addButton.getAttribute("aria-disabled") == "false") {
					clearInterval(i);
					doClick(addButton);
				}
			}, 100);
		}
	}, 100);
};

function checkElement(ele) {
	if(!ele.classList) return;
	
	var linkButton = ele;
	if(!ele.classList.contains("e-ja-p") || !ele.classList.contains("e-ja-p-C")) {
		linkButton = ele.querySelector(".e-ja-p.e-ja-p-C");
		if(!linkButton) return;
	}
	if(ele.querySelector(".ext-censor-button")) return;
	var button = document.createElement("button");
	button.setAttribute("role", "button");
	button.setAttribute("class", "e-ja-p ext-censor-button");
	button.setAttribute("title", "Censor");
	button.textContent = censorChar + censorChar;
	button.setAttribute("style", "border: none; top: -10px; position: relative; padding: 0; margin-right: 8px;");
	button.addEventListener("click", onCensorButtonClick, false);
	linkButton.parentElement.appendChild(button);
}
//checkElement(document.body);

function uncensorPost(a) {
	var content = a.parentElement.parentElement.parentElement.parentElement.querySelector(".rXnUBd");
	var uncensored = a.href.substr(urlPrefix.length).split("/");
	var uncensoredPos = 0;
	var result = document.evaluate(".//text()", content, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
	for(var i = 0; i < result.snapshotLength; i++) {
		var text = result.snapshotItem(i);
		var match = null;
		var pos = -1;
		var str = null;
		
		while((pos = (str = text.nodeValue).indexOf(censorChar)) >= 0) {
			if(uncensoredPos > uncensored.length) return;
			var end = pos + 1;
			
			while(str.charCodeAt(end) == censorCharCode) end++;
			
			var p = text.parentNode;
			if(pos > 0) {
				var beforeText = document.createTextNode(str.substr(0, pos));
				p.insertBefore(beforeText, text);
			}
			text.nodeValue = str.substr(end);
			
			var span = document.createElement("span");
			span.textContent = decodeURIComponent(uncensored[uncensoredPos]);
			span.setAttribute("style", "background: black;");
			p.insertBefore(span, text);
			
			uncensoredPos++;
		}
	}
}

function checkPosts(ele) {
	var censoredPosts = ele.querySelectorAll("a[href^='" + urlPrefix + "']");
	for(var i=0;i<censoredPosts.length;i++) uncensorPost(censoredPosts[i]);
}

document.body.addEventListener('DOMNodeInserted', function(e) {
	if(!e) e = event;
	if(!e.target.classList) return;
	checkElement(e.target);
	checkPosts(e.target);
}, false); 

checkPosts(document.body);

使用方法：
安装后 G+ 发贴框右下角会增加 『██』按钮。
先选中你想要涂黑的文字，然后点击『██』按钮，即可将这些文字涂黑。
鼠标悬停可以确认原文，右键点击则可以还原。
涂黑文字后，点击发贴按钮并不会立即发贴，而是会添加一个链接。
这个链接中包含了被涂黑的内容，所以不建议去除该链接。除非你不希望别人查看原始内容。
如果觉得链接的图片和说明很烦，可以去除，但链接本身不能移除。
当链接添加完成后，再次点击发贴按钮即可发送。

还原方法：
首先必须确认那个帖子包含一个到 SOPA Strike 的链接。
安装这个脚本后，选中被涂黑的文本，即可看到原来的文本。