Wikipedia-Watch.org owner, Daniel Brandt has published a report showing widespread plagiarism in Wikipedia.

A more sophisticated methodology could be used here. One idea that has just hit me would be using archive.org and the Wikipedia history function to discover phrases that appeared on other sites first. This could be all automated.

But such activity should be applauded. Whatever people may speculate about Daniel Brandt's motives, the same thing could have been done by a Wikipedian with the same positive effect: as an open system that assimilates criticism, it will learn and evolve from negative press out there. And as a fast moving encyclopedia, it can react quickly to address the problem.