Tim Starling wrote
If we protect user pages, we can expect vandals to vandalise talk pages instead.
Right. The graffiti, if that is what they are, migrate. Of course if they are nasty personal attacks and repeated, user pages can rightly be protected, and sanctions applied. Proposal: do _not_ make user pages uneditable as default. This is the 'soft security' approach, which generally has served wikis well: don't try to block out all the user problems, because you won't.
Charles