Take 1. Thanks to Dubner and Levitt, NYTimes readers have a chance to learn about the unintended consequences associated with the Endangered Species Act:

Dean Lueck and Jeffrey Michael wanted to gauge the E.S.A.’s effect on the red-cockaded woodpecker, a protected bird that nests in old-growth pine trees in eastern North Carolina. By examining the timber harvest activity of more than 1,000 privately owned forest plots, Lueck and Michael found a clear pattern: when a landowner felt that his property was turning into the sort of habitat that might attract a nesting pair of woodpeckers, he rushed in to cut down the trees.

Take 2: Account of journalist Ezra Levant who is supposed to divulge his motivation for publishing a cartoon:

What a strange place Canada is in 2008, where the police care more about human rights than the human rights commissions do, where fundamentalist Muslims use hate-speech laws drafted by secular Jews, and where a government bureaucrat can interrogate a publisher for 90 minutes, and be shocked when he won't shake her hand in greeting.

Take 3: Fellow blogger Mike Munger's take on McCain-Feingold (posted a year ago, but pertinent given recent results in SC and elsewhere):

BCRA (McCain-Feingold) is bad politics, bad regulation, and bad democracy. The law as it now stands makes narrowly focused interests more powerful than they have been at any time in U.S. history, because of the power of money and television. Where political organizations at one time had to work mostly on mobilizing partisans, in the 21st century electronic means of communication have reduced the transactions costs of politics to the point where organized interests can focus on single issues.

Of course, one needn't be very cynical to suspect that the unintended consequences of BCRA were not unintended by all who supported it.