Wiki is community, its a collaborative local or global common.
There are a number of website security options, but a wiki has to be open or it doesn't work ...
- Url Approvals - Require approval of Url links
- Blocklist - Blocking IP addresses, phrases, and expressions to counteract spam and vandalism.
- Notify - How to receive email messages whenever pages are changed on the whole wiki site, individual groups or selected watchlists of pages
- Page history