OpenBTS and Ettus USPR (software defined radios) have made it inexpensive enough for hobbyists to set up cellular base stations at Burningman.

The difference between an open source base station, and a homebuilt stingray in negligible.

While a grand or two's worth of radio hardware and however many weekends/evenings spent getting it all set up and the a software configured is _kind of_ expensive - it's effectively free at criminal org, corporate espionage, or state levels of action.

Try less than $200. LimeSDR Mini or a couple Motorola C123s running Osmocombb with a filter swap...or a hacked femtocell

Not even that, if you want to use them as a MitM just broadcast the data you want and any arbitrary receiver will pick them up that can't be pinpointed.

That's assuming you don't mind losing the transmitting hardware.

I think we're saying the same thing.

I am not familiar with this term, “black-throw”, can you elaborate?

blackthrow or svartkast is a term for a device left behind in potentially hostile territory to continue operating until it is discovered or fails

For example an imsi catcher spliced into 120vac power and stuffed up into a ceiling tile in a busy shopping mall. I bet that with a stepladder, a clipboard and two guys in high visibility vests, a set of electrician tools, you could do this at nearly any mall in America.

Bonus points for installing a few near each other, configured to operate identically, but at different times.

How do you get the sniffed data, though? You're gonna need some form of high bandwidth uplink.

One option might be to have the sniffing device setup with a hidden wireless network (of some sort).

Then when you walk around, sit in the food court eating, or if the device is close to the outside, sit somewhere out of sight of the cameras with a strong wifi antennae and grab whatever data.

Unless they have some "free" wifi that the device could hop on to send it to some server somewhere.

Using that and / or 4g would make it easier to find the device and, of course, the person though.