Anonymity not possible for accused copyright infringers
In the post "RIAA Can Unmask Anonymous File Sharers, U.S. Court Rules" the news is that one cannot maintain one's anonymity if accused of infringement. The defendant attempted a defense based on right to privacy, but it did not hold up.
http://www.switched.com/2010/05/03/riaa-can-unmask-anonymous-file-sharers-u-s-court-rules/
Here is a link to the decision, posted on Legal Eagle
http://www.leagle.com/unsecure/page.htm?shortname=infco20100429089