I'm happy to be proven wrong here where whistleblowers can only use the PSTN. They already, I would wager, universally would not. They use Signal. All the repor

I'm happy to be proven wrong here where whistleblowers can only use the PSTN. They already, I would wager, universally would not. They use Signal. All the reporters publish their Signal usernames and not their phone numbers. Why? Probably because the PSTN as normal consumers can access it, is pretty non-anonymous. The best case for anonymity is a burner, but you have to buy those burners somewhere that probably has CCTV, or order them online with a paper trail, so it's pretty risky for someone who needs assurances of anonymity. No whistleblowers are using SS7 trunks to place anonymous calls.