Someone not afraid to say what's on their mind ... I like it.
Going slightly off-topic here ... anyone here have other people (children/roommates, etc.) using your access point to gain access to the Internet? If so, what do you (or should you) do to prevent receiving such a letter? I can imagine a scenario where roommate A gets blamed for downloads that were actually attributable to roommate B.
Just downloading something doesn't mean your going to get a letter. There are many people who actively subscribe and pay for access to p2p networks that are based at various places around the world. For example, there is one based in Australia that my brother uses. It's one thing when you log in anonymously, but you would be surprised how many people leave an identity trail. Also, in order to enforce such letters they would have to sue you in small claims wherever you live (at least in the US) in the event you do get one and do not pay. At that point you can argue as to who actually downloaded it. In the end, I don't think it will get to that point. They aren't going to spend the money to actually sue you. It's worth it for them if only 1 out of 10 would just pay up.
In addition, some nations have laws that state that regardless of whether they can track your ip, unless they can prove you actively facilitated the download your safe.
I wouldn't worry about it. In my opinion if people are stupid enough to not secure their network and someone uses it for bad things, then they should pay a stupid tax. And for actual pirates, I've got no pity for them.