..say Superantispyware, Malwarebytes, and Trend Micro's Housecall online virus scanner.pretty neat. Go Oprah - I think she should have been the oracle in the matrix.
I mention the first two tools because they almost always bring immediate results when someone complains to me about PC slowness, browser hijackers, and other computer maladies. I recommend an online virus scanner like Trend because it is free and does not interfere with any anti-virus software that may already be installed on a participant's machine.
Getting back to the numbers: If 4 million Oprah viewers -- a fraction of her viewership -- were to run these tools -- and just one in 25 respondents found and removed a bot program -- that could potentially clean up 160,000 systems. That's almost equal to the size of the largest botnet in circulation today, the Cutwail botnet, which currently controls an estimated 175,000 computers, according to research by Joe Stewart, director of malware research at Atlanta-based SecureWorks.
Edit: Oh yeah - here's the link to Krebs' full post.