DENSER THAN OSMIUM

So I'm giving a math test today. As I distribute the test I tell this kid J, to put away his fancy little touch screen phone and take out his calculator. He does. And then half way through the test, what do I see? Why it's J, diddling his phone under the desk! I ask him what he is doing. He says, "I'm just texting a buddy." Astonished by his reply, I laughed right in his face. Because I didn't know what else to do.

Who are these people??