The fact that ISPs are evaluating an Anti Botnet Conduct Code means their are feeling responsible for what resides inside (and leaves) their networks, and hence are supposed to take technical, organizational and educational countermeasures.
Few days ago I have discovered that the City I live in (Rome), ranks at number two in the World for the number of BOT infections, at least according to Symantec Internet Security Threat Report Edition XVII.
Of course reports must be taken with caution, but it is undoubted that Bot infections are becoming a huge problem for the Information Security Community (a modern Biblical Plague), so huge to deserve the attentions of The Federal Communication Commission. As a matter of fact, on March 2012, FCC, working with communications companies including Verizon, Cox, and Comcast, has passed a voluntary code that delineates the steps that ISPs must take to combat botnets. As you will probably know, botnets may be used by cybercrookers for making money with different criminal purposes ranging from information theft to the execution of DDoS Attacks: have a look to this interview to a botnet operator to have an idea (and to discover that botnets are used also to counterfeit virtual currency).