You may have been hit with spam that advertises a URL in which the domain is a large number. Your efforts to complain may have been met with frustration because you can't figure out where to complain to. What you may not have realized, is that the large number is the decimal equivalent of the IP address. What a royal pain to translate by hand, converting it into bytes, and then translating each byte back into decimal! But, how easy to do by computer! To see just how easy, check out domtrans.java.