I'm not even a person who works in coffee shops very much, but I can't help but think that this is kind of jerky behavior, and loses customers.
I'd also like to point out that a place that was "laptop-free" in my town (note: college town) WENT OUT OF BUSINESS VERY QUICKLY. And I do not like going to the place that has 4 designated laptop-free tables "so you can drink your coffee and read the newspaper." Nobody ever, ever uses them for anything. And yes, everyone else is crammed in the back. Ugh.