Merge pull request #157 from w3c/clelland-mitm-121

Add note about transparent MitM proxies

Author: miketaylr

index.html

@@ -2043,7 +2043,11 @@ <h2>Privacy Considerations</h2>
       processing the <a>request</a>.  For errors during <a>DNS resolution</a>, a
       NEL report only contains information available from DNS itself.  This
       prevents <a>servers</a> from abusing NEL to collect more information about
-      their users than they already have access to.
+      their users than they already have access to. Note that NEL reports will
+      include a web site's public IP address in the <a>report body</a>'s
+      <code>server_ip</code> field, which may not always be known to the service
+      which generates the NEL header, for example if it is behind a load
+      balancer or other transparent MitM proxy.
       </p>
 
       <p class="note">