[Mediawiki-l] Delete passive users ?

[GraphoPhile]

 Jani : Does this not provide a fine attack against Mediawikis: make a bot
that generates and register users. After some trillions of random users
added the wiki is on its knees.
GP : From Rob answer I understood that the problem is for links that are
created in the system when a user is active.
If a bot "just" adds trillions of users I guess he's got no time for
creating pages.
So these passive users could be erased ???????
The need is of an alarm indicator of "over registration of users".