found this on twitter: https://x.com/Hannibal9972485/status/1970540224867365060

no idea if its accurate. the replies appear to be disagreeing with it

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It’s a Telecom Bypass Scam Using SIM Farms…Grey-routing is when international calls are re-routed through SIM farms like the one in those photos, instead of going through legitimate telecom carrier infrastructure.

Someone overseas makes a call to a U.S. number Let’s say someone in Nigeria calls a U.S. bank or friend.

Normally, the call would be routed through official international telecom carriers, and each leg of that call would cost money.

The person calling (or their carrier) pays international calling fees to reach the U.S. phone network.

Scammers hijack the call and reroute it through their SIM farm

Instead of going through legit U.S. carrier infrastructure like AT&T or Verizon, the call:

Enters a VoIP (internet call) gateway.

Is then re-routed to one of the SIM cards in the SIM farm, which is sitting on U.S. soil and connected to a local mobile network (like T-Mobile or Boost).

This SIM answers and makes the call look like a local one like it’s just a guy in Houston calling a local pizza shop.

The call completes, but the real telecom carriers get screwed

The call appears as a local mobile call on U.S. networks, not international traffic. For the record, someone may find this interesting.

The scammers avoid all the expensive international “termination” fees.

The telcos (Verizon, AT&T, etc.) get paid nothing, because it looks like local traffic.

Meanwhile, the grey-router charges the VoIP client a discounted rate, pockets the cash, and repeats the process at scale.

> Scammers hijack the call

How do you do this bit? Is the caller deliberately cooperating, or they think they're using a real service?

I remember calling transcontinentally in the noughties - I would top up an international calls account. If I recall, I had bought a card from a shop with a scratch-off panel. To call first call a local number, then enter my account number. I would pay local rates for the call which were bundled with the contract, so free on the margin, and the call would cost me some pennies per minute from my calls account.

I have no idea how they completed the call, but I was thrilled as it was just before the time when you could just use apps, and the calls would have been ruinous otherwise. For all I know the whole network was a scam. Things like phone cards, money remittance etc, all seem pretty scammy anyway at the best of times.