For those who don't know, Mr Colbert, in his faux-news show The Colbert Report (he pronounces each word with a silent "t"), presents himself as having wingnut views that he doesn't actually have, and thus lampoons those ideas. This is satire. He gave quite a speech at the White House Press Club dinner a few months ago, wherein he ribbed Dubya by pretending to speak in support of him... satirically.
This is not the same thing. When you go on television and say, "Hey, viewers, go vandalize some Wikipedia entries," you've crossed a line, much as if you'd suggested that they scrawl graffiti on the US Capitol building, or that they stand in the middle of Pennsylvania Avenue and block traffic. It's not journalism, and it's not comedy. It's just an irresponsible use of a position of influence.
Yes, Mr Colbert, we know that people watch you. We know that they pay attention to what you say. We know that if you say something on your TV show it will hold more sway than anything I will say here. And that's why you shouldn't say just anything you feel like saying. That's why you have to use your influence responsibly.
In fact, Wikipedia is quite useful. And in fact, once the viewers of The Colbert Report took down some Wikipedia servers, the Wikipedia overlords dealt with the situation, and all is again well. We know it's not perfect, and we know that people can put bogus information into it. Even so, it's a useful resource that works surprisingly well despite its chaotic manner of updates and maintenance.
In branching out from skewering politics to attempting to skewer technology, Mr Colbert's just gotten foolish.