[pmwiki-users] Preventing vandalism

[porneL]

I've got trouble on my wiki - stubborn vandal keeps deleting pages  
(replaces large portions pages with something like "sfsafsfs").
I can't block him by keywords. I can't block him by IP, because he has  
dynamic IP within popular network range.

I can't find any recepies that could help in this situation. Are there any?

Is it possible to quickly revert ALL changes since given date? or all  
recent changes from certain IP?

Where can I hook-up my code to implement "lameness filter" or block edits  
that remove most of page's content?

-- 
regards, porneL