Yeah absolutely. I’ve seen that as well and it’s very concerning. You need layers of security. Especially if the private APN doesn’t have P2P traffic blocked, as otherwise a single field-compromised device becomes an ingress point.

Nonetheless, miles better than devices on the public net. Especially when compared to devices with public static IPs that don’t even have the protection of the carrier’s cg-nat.

That’s one of the two definitions, see: https://en.wikipedia.org/wiki/Air_gap_(networking) And https://www.ibm.com/think/topics/air-gap

air-gapped networks are networks that have been isolated from all external networks, including cloud and wifi. Air-gapped networks are disconnected from the internet and provide a strong layer of protection from a broad range of cybersecurity threats.

In any case, pedantry aside the point stands that it’s possible to connect these in a way that’s isolated from the public internet.

You’re in your own VRF in the cellular ISP’s network. You typically get one or more RFC-1918 private subnets to assign IPs to your devices from. You can set strict ACLs on those devices. They have no internet access and can only communicate with each other (if you allow it) and optionally your network via carrier peering. The carrier peering is typically BGP over IPSEC or MPLS (although good old fashioned carrier hotel cross connects are also an option)

I’m assuming you were asking a serious question and so I provided a serious answer. Hopefully you find it interesting.

Source: I design cellular private networks for a living.

Can’t speak for the situation in other countries, but in the US as a business you can get a cheap lte modem and put it on a custom APN that’s completely airgapped (as in: inaccessible from the public internet) for less than $1/mo/sim with fairly minimal setup costs. So I agree, this is just silly that these are on public networks.

Original welcome email on my Gmail October 2005.

Subject was “Gmail is different. Here’s what you need to know.”

This isn’t exactly what you’re looking for, but since there’s already been numerous good suggestions here’s a slightly different one:

I thoroughly enjoyed Death Road to Canada co-op.