When autoblocked, the user gets 'autoblocktext' message:
You do not have permission to edit this page, for the following reason:
Your IP address has been automatically blocked because it was used by another user, who was blocked by Saper. The reason given is:
Autoblocked because your IP address has been recently used by "Test1".
The reason given for Test1's block is "testing autoblock message"
• Start of block: 22:55, 27 October 2013
• Expiry of block: 22:55, 28 October 2013
• Intended blockee: 2A01:198:200:15F:0:0:0:2
You may contact Saper or one of the other administrators to discuss the block.Special:BlockList reveals:
</tr></thead><tbody> <tr> <td class="TablePager_col_ipb_timestamp">22:55, 27 October 2013</td> <td class="TablePager_col_ipb_target"> <a href="/trunk/w/index.php?title=User:Test1&action=edit&redlink=1" class="new mw-userlink" title="User:Test1 (page does not exist)">Test1</a> <span>...</span></td> <td class="TablePager_col_ipb_expiry">22:55, 28 October 2013</td> <td class="TablePager_col_ipb_by"><a href="/trunk/w/index.php?title=User:Saper&action=edit&redlink=1" class="new mw-userlink" title="User:Saper (page does not exist)">Saper</a> <span>...</span></td> <td class="TablePager_col_ipb_params">account creation disabled, cannot edit own talk page</td> <td class="TablePager_col_ipb_reason">testing autoblock message</td> </tr> <tr> <td class="TablePager_col_ipb_timestamp">22:55, 27 October 2013</td> <td class="TablePager_col_ipb_target">Autoblock #10</td> <td class="TablePager_col_ipb_expiry">22:55, 28 October 2013</td> <td class="TablePager_col_ipb_by"><a href="/trunk/w/index.php?title=User:Saper&action=edit&redlink=1" class="new mw-userlink" title="User:Saper (page does not exist)">Saper</a> <span>...</span></td> <td class="TablePager_col_ipb_params">account creation disabled, cannot edit own talk page</td> <td class="TablePager_col_ipb_reason">Autoblocked because your IP address has been recently used by "<a href="/trunk/w/index.php?title=User:Test1&act ion=edit&redlink=1" class="new" title="User:Test1 (page does not exist)">Test1</a>". The reason given for Test1's block is "''testing autoblock message''"</td> </tr> </tbody>
This was just an autoblock on 2A01:198:200:15F:0:0:0:2 (Autoblock #10) and originally this block was intended to block "Test1".
Now, because we know which block is the parent to the autoblock, we may
give "the real culprit" and avoid disclosing IP address (see similar privacy issues in bug 53008).
It seems to me that providing the parent block target instead would be better.
See Also: T55008