Wikimedia Bugzilla is closed!

By clicking in once place all changes made by a particular user will be reverted
within a certain timeframe.

This is NOT a feature for Wikipedia, but for many small sites that use mediawiki
for their own user manuals etc. It is a pain when link spam bots create an
account and then deface 10s of pages with spam and then the admin has to go
through and revert each individual page. Example of spammers contributions:
http://www.pymolwiki.org/index.php?title=Special:Contributions&target=Lizator

Many of these small sites have been reduced to emailing the admin for an account
because of massive amounts of robot vandalism. Sites are having to resort to
extreme measures. For example, http://lincity-ng.berlios.de/wiki/ posted the
following:

 6. January 2006 - Due to spam attacks it is no longer possible to create
accounts. Contact us if you need one.

 9. January 2006 - Editing and Creating Accounts is allowed for anyone again.
But we have installed a strict spam blocker: Only users with admin privileges
are allowed to post links that contain http: // Ask us for admin privileges if
you want to post external links.

Likewise, http://www.pymolwiki.org:

 The PyMol Wiki actively seeks new users and contributors! However, due to
massive amount of spamming, we've changed the registration process, until
further notice. If you would like access, you will need to be verified by a
system administrator/sysop. To do so, email ... (and tell me why you use PyMol).
Also, be sure to include your desired user name, real name, temporary password,
and email address. Once we figure out a way to automatically prevent spamming,
we'll return to the normal method of registration.

vossman