To make a long story short, for over a year someone has been trying to sabotage my relationship with my boyfriend. They have created multiple e-mail addresses to send e-mails to us, impersonating me and just general harassing. The police originally did not take my concern seriously, but finally after bringing them a year's worth of e-mails, they have gotten involved. They just recently sent in a subpeona to the cable company that the IP address led them to. We are waiting for that to come back and hopefully it will lead us to the residence of the person who has been doing this. My question is this: If this person wasn't sending the e-mails from home, but rather from their cell phone, or let's say, using WI-FI at Caribou, is the subpeona going to be worthless? Or will we still be able to find out WHO has been doing this for sure?
If they have a record of the IP addresses and which ISP's those belong to, they'll be able to find them (open WIFI will be a little more difficult). I'm not sure if there is an 'official' amount of time ISP's are suppose to keep IP address assignment logs so it's probably best that they start with the most recent and work their way back.
There's a log somewhere. It's just going to take diligence on the part of the police.
Good luck. Please let us know how it turns out.