The Koch brothers are mostly unknown. It is a known fact that they have at
least one professional PR firm (New Media Strategies) working to monitor their Wikipedia presence. That's certainly within their rights, and can be within the Wikipedia rules. It is Ken's assertion that there are "many people highly motivated to write misrepresentations and unbalanced articles," though the evidence seems to point to there being maybe a handful of such people.
The article "Political activities of the Koch family" does not show that much activity.
I don't know much about them, but they don't seem to sneak around saying one thing and doing something else; that cuts way down on the uproar.
Fred