There's a hidden Android setting that spots fake cell towers

That's a just incredibly naive.

Because the door being open makes it possible for opportunistic thieves and even kids to steal something. If the police knocks on it, it's actually better to open it. Otherwise they will still get in, but you will also not have door after that.

With phone interception, I can't imagine any other actor being sophisticated enough to bother with setting up the stringray thingy. Maybe something very targeted to get somebody very special (having a hot wallet with 20 bitcoins and going around the city with it comes to mind), but I would still expect the simplier methods there too.

Add: Even with the normal HTTP traffic, mitming was way more common and more practically exploitable back in the day, just by setting up a rogue wifi AP and fishing for passowrds. I'm not sure it was ever a thing with stringrays when non-government actors did something with them.

> the government if they serve the cell phone company with a warrant or other legal proceedings

The police may have to sometimes jump though a couple of rubber stamped hoops, or hand over stacks of taxpayer money to companies for access to their online law enforcement portals, but the government is already inside taking everything that passes through those companies, using hardware those companies have been forced to install and/or by the outright seizure and occupation of their private property. There's nothing constitutional about it, but this has been true for a very long time (https://en.wikipedia.org/wiki/Room_641A) and it's not going to change.

>All of these problems have been solved on the web

Have they? The solution to IP addresses is basically "use a VPN", which you could do also on a phone. SNI leaks have been around since forever, and despite eSNI, still isn't close to being widely fixed. There's MAC address randomization, but only because LANs and wifi networks are basically an unregulated free for all, so spoofing doesn't really matter. It's far less viable with controlled access networks like cellular. Some countries even have regulations banning spoofing/changing IMEIs.

They haven't been solved on the web. Mobile phones have to authenticate themselves with the carrier to ensure someone is paying for their connectivity. Therefore they can't be anonymous. On the other hand, indeed, most of the time you don't have to identify yourself to connect to a web server — but once you have connected, you may face a paywall that requires authentication! Also, you are certainly authenticating yourself somehow with your ISP for your home internet connection.

This doesn’t mitigate the issue that a malicious base station poses by downgrading a phone.

It doesn’t matter what the network supports. It matters what the phone supports

Real time collection and less legal friction?

Stingrays are use to intercept calls in real time. They are used by police and foreign intelligence agencies. It allows them to listen in on political calls. Washington DC is a haven for fake cell phone towers.

I found out the LEO in the area I was in had at least one. I saw a police car parked in the area I was in. Very out of place and would only be there if there was a house call. Decided to test the waters, went out side, paced back and forth, and kept talk. His face and body language changed dramatically which let me know he was using a Stringray and I was the current target without a warrant.

Never turn off your phone if you think you're in trouble; this creates an anomaly in the data, akin to acoustic shadow.