So, three cold callers yesterday (land line). One called right after 8am. I can't block them because I run a company from home and do-not-call-list rules only applies to private numbers (NIX in Sweden). I don't have time to play games with them, so I think I'm just gonna tell them to wait, resume my work, then hang up after 2 minutes. Hanging up quickly only gives them more time to harass others.
I'm thinking I can get them to stay on longer if I leave the phone next to a radio or a sound source. I might have to do some experiments with a stop watch and graph paper ready.
A warning though: Some scammers specialize on calling from a pay number and hang up before you can answer. If you call them back to see what it was about, they try to make you wait and since you're the one calling, you'll be the one paying (probably a lot per minute too).