In 2001 Ian Ayres, a professor at Yale Law School, took to the opinion pages of The New York Times to record his displeasure with those students who use their laptops during class to surf the Internet, play games, e-mail, or even trade stock.

Ayres now has a prominent supporter in Saul Levmore, dean of the University of Chicago Law School, which has taken the step of blocking Internet access in most of its classrooms. Levmore notes that Internet usage "appears to be contagious if not epidemic" during classes.

In praising Levmore's decision, Ayres stresses that there is no good a priori argument against multitasking. "The case is at best an empirically-informed hunch about what is the best way to teach. I see some power to a parentalism argument that teachers should ban surfing because it impedes students’ ability to learn," Ayres writes on the Freakonomics blog.

But Ayres does concede that some of his more crafty students have come up with a plausible argument in favor of laptop-based distractions in the classroom: If he is forced to compete with the Internet for his students attention he will have more incentive to be an engaging presence in the classroom.