Thread:Project:Support desk/Too much traffic/reply (7)

You don't have to sacrifice user freedom, although if you are prepared to do that, you problem will most likely be solved once and for all. There's normally no need to restrict editing to sysops - if account creation is locked down then  is normally enough.

If you want to keep a more open wiki, you should at least install SimpleAntiSpam, which apparently blocks the dumb varieties of spambots; and a captcha extension, which if set up properly, will require the solution of a captcha before you can create an account or add external links to pages.

Read the Manual:Combating spam page in full before reopening your wiki.

If I were you I would also check out Google Webmaster Tools. That spam can't have done any good for your Google ranking.