Ask HN: Why is my IP banned?

From my usual host, I get a 403 Forbidden:

  $ curl -i https://news.ycombinator.com
  HTTP/1.1 403 Forbidden
  Server: nginx
  Date: Sat, 23 Mar 2013 17:15:46 GMT
  Content-Type: text/html
  Content-Length: 162
  Connection: keep-alive

  <html>
  <head><title>403 Forbidden</title></head>
  <body bgcolor="white">
  <center><h1>403 Forbidden</h1></center>
  <hr><center>nginx</center>
  </body>
  </html>

However, if I access it from a different IP or via Tor, everything works nicely and I can even log in. Wouldn’t it make more sense to ban my account if you™ don’t like me? :)