IP Traced With DSL

I know there has been discussion in the past that a non-fiber DSL line can't be traced back to you based on IP address. Is this true or someones lame guess that spiraled out of control? If it is true, why doesn't CL use it to C&D those that over post or those that phish for personal information? I ask because I got called the other day from a movie company saying that I downloaded some copyright movie and they said they were going to sue me. I didn't admit anything and even talking further, the guy seemed to be a total idiot. I mentioned I had wireless and someone could connect to it w/o my knowledge. He told me that it was impossible to download a torrent over wifi because it wasn't fast enough. I laughed @ what he said and ended the call shortly after. It was basically a threat call and he told me to get a lawyer, even though he refused to send me anything in the mail. I'm not worried about them suing me, I just want to know the DSL IP thing. Can they trace it to you directly or do they just get everyone's info on your node that could connect with that specific IP address and call everyone looking for someone to admit guilt?

I was reading this morning - that basically they log everything - but most times nothing is done about it. But should the information be subject to a lawsuit then they could trace it back to you.

Really if you don't get anything in the mail - then not being a legal expert or anything - I'd say that's just a scare tactic at this point. Once you get something in the mail though "registered" or served to you -- then you best be moving directly to an attorney for advice.

Sorry can't be more help --- just depends in who's crosshairs you find yourself in more than anything.