Thanks, that was the part I was missing. In my country ISPs cannot tell _anyone_ which user has a specific ip at a specific time, they need a order from a judge based on a police request.
In the US it is not the ISPs "telling" the identity of the customer. They just forward the notices/warnings/thinly-veiled-threats to them. They don't let them know who the IP address is/was held by without a court order as far as I know.
Umm... mind telling me what country you're in?
I was specifically referring to Switzerland and Italy.