> 100,000 SIM cards housed in “SIM servers

> all being within 35 miles of midtown Manhattan

Firstly, these are in fixtures that hold 4 or 8x as many SIMs as radios, so they can’t all be online at the same time.

How many SIMs are active ~35 miles of Manhattan?

Crashing the cell network is fear mongering.

Here’s what I think they’re mostly used for: gray market VOIP termination. Get an unlimited plan and charge US call termination at 0.5 cents/minute. There are 44000 minutes in a month so your potential gross revenue is $220. Sure you can’t run it 24/7, but plans are a lot cheaper.

Then get darker:

As youre doing that, charge for premium SMS reception, ie: validating new Uber or Gmail or whatever accounts as the numbers are “fresh”. Then after that, probably SMS spam.

That’s all low bitrate and easy on the towers until you get creative with data. Big companies have no choice but to be more lenient on mobile traffic because it’s all CG-NAT’d. You can’t do IP bans unless you want to block entire providers and block legit users.