Wikimedia Bugzilla is closed!

http://en.wikipedia.org/w/api.php?&action=query&list=users&ususers=127.0.0.1

returns:

<?xml version="1.0" encoding="utf-8"?>
<api>
  <error code="internal_api_error_MWException" info="Exception Caught: Database::makeList: empty input">

#0 /usr/local/apache/common-local/php-1.5/includes/Database.php(1237): Database->makeList(Array, 1)
#1 /usr/local/apache/common-local/php-1.5/includes/api/ApiQueryBase.php(131): Database->select(Array, Array, Array, 'ApiQueryUsers::...', Array)
#2 /usr/local/apache/common-local/php-1.5/includes/api/ApiQueryUsers.php(93): ApiQueryBase->select('ApiQueryUsers::...')
#3 /usr/local/apache/common-local/php-1.5/includes/api/ApiQueryUsers.php(55): ApiQueryUsers->getOtherUsersInfo(Array)
#4 /usr/local/apache/common-local/php-1.5/includes/api/ApiQuery.php(210): ApiQueryUsers->execute()
#5 /usr/local/apache/common-local/php-1.5/includes/api/ApiMain.php(356): ApiQuery->execute()
#6 /usr/local/apache/common-local/php-1.5/includes/api/ApiMain.php(224): ApiMain->executeAction()
#7 /usr/local/apache/common-local/php-1.5/includes/api/ApiMain.php(209): ApiMain->executeActionWithErrorHandling()
#8 /usr/local/apache/common-local/php-1.5/api.php(77): ApiMain->execute()
#9 /usr/local/apache/common-local/live-1.5/api.php(3): require('/usr/local/apac...')
#10 {main}

</error>
</api>

for any anonymous user.

It would be nice to be able to retrieve information (edit count in particular) for anonymous users through the API. If this is not possible, it should fail a little more gracefully.