You can ask one end (typically the service end) for timestamp and local and remote port and IP address. Then you ask ISP to lookup subscriber info (via account

You can ask one end (typically the service end) for timestamp and local and remote port and IP address. Then you ask ISP to lookup subscriber info (via account id) based on that. You can do that already in some EU countries, just by lodging a complaint with police as a service provider (say you have an e-shop) for example. ISPs have to store these logs for some months.