As others have mentioned, clicking through to their profile and using any contact details they&#x27;ve left is the best bet for this.  If there&#x27;s no information there, they probably don&#x27;t want to be contacted.  But if you&#x27;re someone who does want to be contacted, there are tools you can use to make sure you don&#x27;t miss anything here:<p>* HN Alerts will send you an email whenever someone replies to one of your comments: <a href="http:&#x2F;&#x2F;www.hnreplies.com" rel="nofollow">http:&#x2F;&#x2F;www.hnreplies.com</a><p>* HN Watcher, monitors HN posts for keywords, or you can follow certain users &amp; have their comments &amp; submissions emailed to you: <a href="http:&#x2F;&#x2F;hnwatcher.com&#x2F;" rel="nofollow">http:&#x2F;&#x2F;hnwatcher.com&#x2F;</a><p>I don&#x27;t want yet another inbox I have to check (ie HN private messages!), but listing contact details in my profile &amp; having alerts sent to my email has been really useful to me.