If a student can Facebook through your whole class and still make an A, whose problem is that?
A few years ago, professors noticed that fewer students were taking notes. Instead, if they needed to recall information, they were looking it up online. "Students were basically saying, 'There is nothing you're telling me that I perceive to be of value,’" says George Saltsman, executive director of ACU’s Adams Center for Teaching and Learning. He says the conventional method of teaching — basically, professors telling the students the answers to the upcoming tests — is badly outmoded in the digital age. "In today's world,” he said, “students can look that up any time they want" — including in the middle of a lecture.
"If a student can Facebook through your whole class and still make an A, whose problem is that?" Saltsman says.

I think the accessibility of information is irrelevant. My grandmother had a set of encyclopedias that were constantly available for me to look up information in and I often did. My brother never did. Just because the information is out there and available at any time does not mean that all people will take advantage of it. The format of the information is irrelevant. People who wouldn't pay attention to a lecture or look up information in a book aren't going to look it up with a computer. Some of the people will learn information that matters and some of the people will earn the highest score on Mahjongg Dimensions.
It was only a few years ago that I spent half of my time teaching trying to take phones away. This was until I realized that there was no use. I could take them all I wanted, but it never stopped anyone from texting in class. I found that I had to do something to engage the students. If the class is interesting enough to make the students pay attention and learn, they don't spend so much time on the phones. This doesn't mean that I am an entertainer. I just have to be a better teacher.
I love the question. Teachers need to figure out how to change up the class so students are engaged. Sure, there may be times for lecture, but they should be the exception and not the norm. Project based learning is one way to do this. Another strategy would be to put those Facebook users to work by having them use their network to learn. Students know how this networking thing works where most teachers are in the dark.