[Mediawiki-l] Decreasing vandalism

[Philip Beach]

My wiki is experiencing a lot of vandalism lately. I would like to
implement things to reduce the amount of vandals allowed into the
system. Perhaps limiting the number of edits by brand new users?
Requiring a valid email address by new users?  Requiring a full name?
One thing I would really like to do is to limit the number of
characters in a new user id to less than about 12.

Is there any easy way to do any of this, like an extension or
something already in the software?

Thanks a lot!