No, I'm not actually a Koch Bros. shill (and I can't believe I had to say that)
Earlier today a friend of mine (Eclectablog...who, by the way, is also the head of the best blogging team in America, and who could use your help with his quarterly fundraiser at the moment) noted that there was an anti-ACA banner ad from the Koch Bros running at the bottom of this site earlier today.
His Tweet was intended as snark, of course, but at least a couple of people didn't appear to get the joke, and actually think this means I'm either hypocritical or some sort of 11th Dimensional Chess-playing Double Agent Mole working for the Koch Bros. Not sure how that would work, exactly, but whatever.
The truth is, I have little control over what ads run on this site. Google's Adsense settings allow you to block certain general types of ads, such as porn, dating, religion and so forth, but you generally can't block ads from specific vendors (although there's probably some sort of special cases which arise from time to time, I'm sure).
For instance, I could block all "political" ads if I chose, but that would include ads from the full range of the political spectrum...and a lot of these ads are no doubt masked as being "non-political" anyway.
Furthermore, I actually don't usually see what ads are being run at all, since I'm usually logged into my account at the time (as a reminder, anyone who donates $10 or more will be given a user account which will remove the banner ads completely).