A while back, I had a lot of telemarketers were calling me daily, and I mean A LOT of them.

I got so frustrated with he calls that I decided I had to figure out a better way to handle those calls.

At the time, I was working with a PBX software called Asterisk, which is used to handle hardware interfaces and network applications for phone calls.

I needed a suitable side project and there was a version of Asterisk designed for Raspberry Pi, so I made a fun little answering service for myself.

Whenever a telemarketer called, I asked them to call back later, but to "my personal number", and gave them the number to my phone robot. (which had a pre-paid SIM card in a GSM dongle mounted)

When it received a call, it would play a pre-recorded phrase, wait for 1000 ms of silence and then play the next phrase.
After all 16 phrases had been played, it would start from phrase 7 again and repeat until the caller gave up.

I had this set up running for a while, and then added another robot for english speaking callers.

The calls stopped after a few months.
MISSION ACCOMPLISHED!