Can I use freely information from personal emails and some personal answers
<p><strong>Background story:</strong>  </p>

<ol>
<li><p>Recently I've written some <a href="https://law.stackexchange.com/questions/27391/question-about-using-wikipedia-content-about-cc-by-sa-license-about-its-cop">questions</a> on law.stackexchange. People wrote answers to those questions, and also wrote some comments. I read these things and got some new thoughts from them. I'll refer to these as <em>stack_thoughts</em>. This is the <strong>first source</strong> of some new thoughts about my question.</p></li>
<li><p>Also I wrote partly similar question to some other places through email, and received responses. I read those responses and got ideas which I'll refer to as <em>email_thoughts</em>. This is the <strong>second source</strong>.</p></li>
<li><p>I also asked some questions on a talk page in my profile in Wikipedia. There, one can ask for some help, which I did. And I also received answers, from which I got <em>wiki_personal_thoughts</em>. This is the <strong>Third source</strong>.  </p></li>
</ol>

<p>To normally prolong my working on <a href="https://law.stackexchange.com/questions/27391/question-about-using-wikipedia-content-about-cc-by-sa-license-about-its-cop">this same problem</a>, I need to collect, join, analyze, and use thoughts from all three sources. I need to have possibility, to "formulate" this all thoughts, in all mentioned places. I can do this, in particular by two ways:</p>

<ul>
<li>First. I can just blindly use them, write about them without mention of the sources where I got them.  </li>
<li>Second. Before use all these thoughts I can ask for permission from the authors that are my sources. E.g. I can write a message, to each person who replied on my talk page in Wikipedia, about - can I use what they told me, in some other place, maybe on <em>stackexchange</em>. They might reply with a yes or a no.</li>
</ul>

<p><strong>So question is next:</strong><br>
How can I utilize normally, ethically, and legally information from these three resources (sources)?</p>

<p>I know that there a lot on the internet about using copyrighted text resources - but what about personal email letters, and personal messages?</p>

<p>First of all: Note that user content submitted and published on Stack Exchange is, per <a href="https://stackexchange.com/legal">the terms of service</a> "licensed under cc by-sa 3.0 with attribution required."  Similar open-source licenses apply to wikipedia and many online forums.</p>

<p>Private communications, at least in the U.S., are subject to full statutory copyright protection.</p>

<p>You evince some confusion regarding what copyright protects: It applies to fixed, creative expression.  So if you read a bunch of copyrighted text, and then write something that does not directly copy text (except as subject to <a href="/questions/tagged/fair-use" class="post-tag" title="show questions tagged &#39;fair-use&#39;" rel="tag">fair-use</a>) then you own copyright on what you wrote, even if you were informed by other copyrighted sources.  If the only protection that applies to the sources you used was <em>copyright</em>, then you do not need the permission of anyone, nor do you need to attribute your work to anyone, to digest and create your own written expression of ideas, facts, etc.</p>

copyright