Administrators now have the option of disabling autoblocks for individual blocks via a checkbox on the block form. The 'autoblock' is a problematic software feature that automatically blocks IP addresses used by a blocked account, or accounts operating from a blocked IP address. This caused much frustration for administrators forced to block vandals operating from shared IP addresses or AOL proxy addresses, which sometimes led to the automated blocking of dozens or hundreds of legitimate users.
The patch was originally applied without necessary changes to the database, which disabled blocking on all Wikimedia projects for half an hour. The delay occurred because there were no root users available to apply the fix; the root user who synchronised the original patch was away. Malicious users quickly took advantage of this on the English Wikipedia to test the countervandalism community's ability to track and revert vandalism, but there are no reports of the same occurring on other projects.