Spam Reversion
If you notice that some CLiki page has been vandalized by spammers, you can revert the page to a previous non-spam revision, or delete it if it was created by a spammer. It's generally a good idea to watch the Recent Changes page and look for spam edits; they typically have a URL in the change description or some other nonsense.

To revert a page to a previous revision: use the revisions links at the bottom of the page to find the highest revision number that did not contain spam. Be careful, because sometimes the spammers will add spam links to a page instead of completely vandalizing it, so be sure to scroll down the page and look for any spam links that were added. Once you're at the last non-spam revision to the page, hit the "Edit" link at the bottom. Fill in some pithy diatribe against spam in the "Summary of changes" field, and put your name in the "Your name" field. Hit save, and all will be well.

To delete a page which was created by spammers, edit the page and remove all the content. Deleted pages get put in the Deleted articles list with their history preserved, and can be restored later.