BBC has article on ongoing saga of US Congress making political edits to Wikipedia. Some brief comment, because there's been a lot of criticism focusing on Wikipedia as a source of reference recently, and I think it would be good to separate the issue away from all that.
This article highlights the other side of Wikipedia - the audit trail, rather than the information. The history, rather than the final version. In this instance, the news isn't that Wikipedia can be changed by anyone, it's that the changes made by someone can be seen and published, with a large amount of non-repudiation associated with it.
The lesson to be learnt by people making changes is, of course, to do it through bouncing proxies, disguise your tracks, which I don't think Wikipedia can fix quite so easily. But at least we have here one example of how the versioning system highlights - extremely efficiently - the relationship between governments (and, should they choose to, other firms/organisations) and "public" information.
Can the same be said for other media outlets? How can we check the same audit trail for other Encyclopedias, or for the news and media outlets? We can't. We rely on leaks and suspicion instead.
This is why I like Wikipedia - it's not just about the information, it's about where that information comes from too. It's a process, not a product.