It is increasingly common for vandals to place hyperlinks on wiki pages to commercial sites, presumably to increase their page rank. The site administrator then has to go in and clean up the mess. Lately, this has been happening on the site several times per day.

The placing of hyperlinks in wiki like this is often called "Wiki Spam". See, for example,,

So far, the vandalism seems to be confined to wiki pages. I presume that it is only a matter of time until it spreads to tickets.

Possible solutions: