Here is a list of user pages for users who don't exist. Many of these should be deleted. Many others should be moved to the correct title.

Note that accounts from before mid-2002 were apparently deleted, though Special:Contributions still shows the contribs. The user pages in this case ought to be kept. So be sure to use good judgement when deciding what to do with a user page. As another example, if a user page says a user is blocked, and that user doesn't exist, it's probably good to check Special:Ipblocklist.

Feel free to edit this list if you like.

select page_namespace, page_title, page_is_redirect from page 
where page_namespace in ( 2, 3 ) 
and not exists (select * from user_ids where user_name = replace(page_title,"_"," ")) 
and page_title not like "%/%" 
and not page_title rlike "[0-9]+\\.[0-9]+\\.[0-9]+\\.[0-9]+"