You mean IP addresses of people downloading torrents? It's peer to peer man, if I start to DL the torrent I'll make a connection to you (assuming you set up your client to accept) and I'll see that you're sharing the data.
The "hacked wireless modem" (the term by the way makes me assume you're not hardcore) defence is good, but they don't care about that. By the time you hire a lawyer and get your shit together they'll have met their goal: stopping you from pirating their IP.