This is a what if question....
Let's say I have a youtube account and upload copyrighted music. One day, an artist decides to sue and his lawyer gives me an email to show up in court. The question is, if I delete my youtube account and erase my email, can they still track me down even if I am not well known around the net?
Also, people can't prove you read the email. For all they know, I could be using a different one and never got the message if I don't show up.