A common problem around SharePoint permissions is a site owner deleting ALL the permissions for an item. This means that ONLY a Site Collection Admin can see the item/list/site! This script can be run against each content database to find all the empty permission objects! This could have been done with object model, but it's too SLOW!
select fullurl + '\' + dirname + '\' + leafname, p.acl from alldocs items,perms p, webs w
where
items.Scopeid = p.scopeid
and
acl like 0xF3FE0000010000000000000000000000
and
items.webid = w.id
Enjoy!
Chris