A pager-like device with proper encryption isn't extraordinarily challenging. But planned obsolescence or selling ads is pretty hard to do with this sort of technology, so despite plenty of interest from users, there's not that much interest from companies.

"An information technology worker from Johnson County recently told The Star about the issue after he stumbled across hospital pager information while playing with an antenna, which he bought to get TV channels on his laptop computer. With a simple program, the antenna picks up radio signals that can be digitized.

Except instead of picking up local TV stations, he started seeing things like this, with the patient's and doctor's names included:

RQSTD RTM: (patient's name) 19 M Origin Unit: EDOF Admitting: (doctor's name) Level of Care: 1st Avail Medical Diagnosis: TONSILAR BLEED, ANEMIA, THROMBOCYTOPENIA

It was the personal patient data of a 19-year-old man, broadcast across the airwaves for anyone to read. And it was coming from a local hospital, which was sending the message to a doctor on a pager."

Edit: Yeah I'm not entirely familiar with interference detection, but I would always suspect some HAM somewhere will figure it out and report it.

A single R820T can do about 2.56MHz bandwidth, which is enough to handle both bands simultaneously.