Originally posted by Scott Johnson:
I believe that unless you are in law enforcement and/or have a court order the ISP will not honor a request for this type of information.
Most ISPs will indeed provide this information on court order only. And even then, they fought it for awhile in the court system. In the US, it wasn't until the Digital Millennium Copyright Act started to get enforced that they started to give in.
There are huge privacy concerns, and no ISP want to be known as not being an advocate for their customers.
Henry