If I'm broadcasting unencrypted information through the airwaves and somebody snags that - what am I going to do? I can't really claim my privacy is being invaded just like if I take a megaphone and stick it out my window and start yelling private conversations - I can't be mad at people who happen to overhear said conversations.Are you okay with data mining, eavesdropping, and warrantless information gathering?
Sure - you may need a device to hear what is being sent - but that device in and of itself isn't an invasion of privacy IMHO. The invasion of privacy is sending private information out in a way that can easily be intercepted and listened to/watched.
Now - if there's encryption and they're breaking that encryption - that's an invasion of privacy and would require a warrant IMHO.
I don't know that it's 'tricking' the cells to connect to it because, if so, it would actually have to function as a cell tower for said service otherwise said service would never receive it and, as such, it'd 'fail' to send. It's more likely they're eavesdropping on unencrypted broadcasted communications.
All of this said - I'm not an attorney - maybe there are laws against listening in on unencrypted publicly broadcasted signals that contain private information. Maybe the signals are encrypted and that encryption is being broken - I don't know. I know there are laws regarding wiretapping but generally that requires cooperation of the phone service to let you 'hook in' or you actually have to modify the circuit/connect into it to snag it so it's a little different.
To make an analogy of sorts to make my point of view make more sense to more people... If I am using wifi without encryption and you watch my data being transmitted back and forth between my computer and my access point - what law have you broken? The one violating my privacy in this case would be me by taking no steps to ensure my private communication is private.
If I am using wifi with encryption and you crack that encryption to listen in on that data being transmitted back and forth between my computer and my access point - you're certainly violating my privacy and quite possibly some laws.