I follow some of the discussion of the DDT ban myth, often carried out on Deltoid. The controversy is interesting for the lack of apparent motive for those who spread the myth. Nobody makes or stands to make huge profits manufacturing or using DDT; those who spread the DDT ban myth are not shills for some DDT industry in the way the global warming denial crowd are shills for the energy industry. The best theory I've encountered is that this is an effort to discredit the environmental movement in general, encouraged by factions threatened by environmentalism in other ways (like the energy industry, of course).
I mention this now because Lambert's recent attack on a spreader of the DDT ban myth mentions one example of stupidity so breathtaking I can't help but share it with others. Apparently, this J F Beck fellow that Lambert is criticizing believes that it isn't abusive to call someone a "toady." He even defends this claim when challenged on it, saying on one occasion that "toady" means "sycophant" (which isn't abusive?) and later just sticking to his guns and insisting it isn't abusive without explanation. Even some of his supporters seem confused by his determination on this point.
 For those who are unfamiliar, here's the short version. The myth is that some sort of global DDT ban has been responsible for millions of deaths due to malaria caused by mosquitoes which could have been killed by DDT. In fact, there has never been a global ban on DDT use. Anti-malaria policy is a complicated area in which mistakes have certainly been made, but it is well established that mosquitoes can develop DDT resistance. Such anti-DDT efforts as there have been have primarily sought to ban its use in agriculture, and efforts to prevent such use probably helped make use of DDT against malaria more successful by slowing the development of DDT resistance in the mosquitoes. Even if the efforts to cut down on DDT use did reduce its use for anti-malarial purposes as well (a point which is hotly debated; read Lambert's blog for lots of discussion and links), the resistance issue makes it quite unclear whether using DDT more aggressively would have saved any more people at all, or whether instead any benefits would have been offset by hastening the development of DDT resistance in the mosquitoes.