Do a search for vandalism on google and the first thing you'll find is Wikipedia's vandalism entry. While some forms of vandalism can be viewed as creative or social commentary, wiki vandalism is pointless. Davis wiki has had very few acts of random, pointless vandalism. However, on several instances, vandals have attacked or attempted to remove pages from the wiki which they do not agree with.
There is no point in vandalizing the wiki. The power of a few vandals is no match for thousands of wiki users. By no means does this mean that the wiki is a tyranny of the majority. By nature, the wiki is conducive to constructive conversation and problems can be worked out in an orderly and mature fashion.