Very occasionally, I get phone calls from some dope who's presumably sat on his mobile phone and inadvertently called me.
Shouting/whistling down the phone doesn't alert him that he's connected to someone and putting the phone down doesn't break the connection. If you try to dial out, the idiot is still there until such time as he finally realises or he sits on another button and breaks the connection.
While I take some small comfort from the fact that he might be on a pay-as-you-go phone and his stupidity may have cost him a tenner, I'd rather not have the phone line tied up for 45 minutes.
I have a friend who used to do this to me regularly until I emailed him a transcript of a confidential conversation he had with his boss. But in the case of a stranger or a number you don't recognize, is there any way to break the connection?