I’m not getting into ALL the details but the “repeatedly calling” back and forth between two numbers quite honestly kept me out of jail overseas due to an embarrassing miscommunication and unintended breaking of a local law (backpacking in college, drinks were had, a friend made an ass out of himself if you must know)

I called a local friend, he didn’t answer. I called his wife she didn’t either. Both follow the “don’t answer unknown numbers” rule. As do I.

It wasn’t until I called friend a second time that he answered the phone. His response? “When my wife got a call from the same number back to back is when I started thinking this must be worth my attention.”

This is a nice example of port-knocking: https://wiki.archlinux.org/index.php/Port_knocking.

I wonder if it would be possible to set up something like this more rigorously. Give everyone unrelated two phone numbers. The first never rings the phone. The second only rings if the first was called within the last minute.

Or perhaps just a pin they have to enter in order to get the first phone to actually ring. Basically 2fa for the right to bother me.

With a creative dialplan design one could do this with a private Asterisk installation (asterisk is behind so many of these cheap disposable phone number/voip providers anyway), though I suppose if one wanted to use someone else’s platform and infrastructure it’d be probably less effort with twilio or plivo

>While this is a possible scenario- in my experience most people know to call multiple times - especially if they know that the recipient won’t recognize the number.

I'm surprised robocallers don't do this too

Calling once selects for people more likely to fall for the actual scam.

Also, spamming/scamming in general is a numbers game. It's generally more profitable to move onto the next number on the list than to keep retrying.

They do