Documentation for port scanning

doc/EN/faq.org

@@ -25,6 +25,7 @@
 | [[How is Tor integrated with Freedombone?]]                                                   |
 | [[Can I add a clearnet domain to an onion build?]]                                            |
 | [[Why use Github?]]                                                                           |
+| [[After using nmap or other scanning tool I can no longer log in]]                            |
 | [[Should I upload my GPG keys to keybase.io?]]                                                |
 | [[Keys and emails should not be stored on servers. Why do you do that?]]                      |
 | [[Why can't I access my .onion site with a Tor browser?]]                                     |
@@ -113,6 +114,8 @@ At present Github is useful just because of the sheer number of eyeballs and the
 The source code for this project is experimentally independently hosted, and it is expected that in future the main development will shift over to an independent site, maybe with mirrors on Github if it still exists in a viable form.
 
 Currently many of the repositories used for applications which are not yet packaged for Debian are on Github, and to provide some degree of resilliance against depending too much upon that copies of them also exist within disk images.
+* After using nmap or other scanning tool I can no longer log in
+This system tries to block port scanners. Any other system trying to scan for open ports will have their IP address added to a temporary block list for 24 hours.
 * Should I upload my GPG keys to keybase.io?
 It's not recommended unless there exists some compelling reason for you to be on there. That site asks users to upload the *private keys*, and even if the keys are client side encrypted with a passphrase there's always the chance that there will be a data leak in future and letter agencies will then have a full time opportunity to crack the passphrases.