As far as I can tell, the policy was aimed at laptop owners who were typing all day, and the clack-clack of the keyboard can be irritating.
But iPads and Kindles are also eBook readers, and reading in a Cafe is almost mandatory. If shop owners don't want squatters, then manage their free internet better, cutting off patrons who don't make a purchase after 60 minutes.
Google the headline, you don’t have to register.
I lived in a university town where all the students went to the local coffee shops with their laptops to do hours worth of work. If you just wanted to come in and get a cup of coffee, you couldn’t do so because every seat was occupied by a student.
The best solution to that would be, as you suggest, simply to limit the internet connection time. There was no limit at the university library, but they didn’t want to go there because there wasn’t music in the background, etc. Limiting their internet time at the coffee shop probably would have forced them to move on to the library after an hour or so.
But a Kindle or other e-reader? It doesn’t use anything from the coffee shop (wifi or electricity), and people don’t sit and read them any longer than they would sit and read a paperback or magazine with their coffee.
I remember that there was a bookstore on the Upper West Side that was staffed entirely by disdainful liberals who were outraged when the big stores like B&N and Borders came to New York. They would write articles about how people were supposed to support their crummy little bookstore, which had a limited selection except for the latest leftist raving (of which it would have hundreds of copies) and a staff that thought it was God’s gift to humanity and which openly scoffed at some of the store’s customers. And then they wondered why nobody wanted to shop there...