A couple years ago I would sit at my desk thinking about a really hard problem in silence. The phone rings. Spam call. Every 30-180 minutes another one. If you now think turn the phone off, well not that easy as CEO of a business when people expect you to be reachable.
It creamed my corn so much that I recorded my own voice samples as a senile "Opa Denny" (german grandpa Denny), modelled after Lenny. Complete with background ducks hanging out on the couch to Opas dismay, later in the call. It works on autopilot without interaction because on Asterisk, and with the largest German SIP provider at least, you can extract the calling peer identity from the SIP header. So I wrote a scoring system based on indicated number, black and whitelist regexs for number and for calling peer, greylist for the geographically surrounding number prefixes, etc. A legit mobile call would show up as number@t-mobile.de for example, while a spam call would say fakenumber@01012.com.
Asterisk would record the call in wideband stereo, normalize the audio, and mail it to me as MP3 attachment. Funny for a while, but these days I just throw all such calls onto the mailbox. Since they need a real person to scam or create a sale, the call is finished right away.
It works great to this day, because I never published it.