title: What is the sender in RemoteCertificateValidationCallback?
body: <p><code>ServicePointManager.ServerCertificateValidationCallback</code> is a property of type <code>RemoteCertificateValidationCallback</code>.  The constructor for <code>RemoteCertificateValidationCallback</code> takes a delegate such as</p>
  
  <pre><code>public bool SomeCertificateErrorHandler(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
  {
      return false; // Don't accept any certificates!
  }
  </code></pre>
  
  <p>When this delegate is called, what specific type is <code>sender</code>?  If it isn't obvious from that answer, what use is <code>sender</code> in this delegate?</p>
  
  <p>(Just so there is no confusion, I was being facetious regarding the contents of the method.  I'm interested in the parameters.)</p>