Doom9 sez:

Dutch civil rights organization Bits of Freedom has run an interesting experiment: They put up a text by a famous Dutch author, written in 1871 to accounts with 10 different ISPs. Then they made up an imaginary society that is supposed to be the copyright holder of the author in question, and sent copyright infringement takedown notices to those 10 ISP via email (using a Hotmail account). 7 out of 10 ISPs took down the material, sometimes within hours and without even informing the account holder. One ISP doubted the legitimacy of the claim and asked for some proof that the alleged plaintiff was in fact the copyright holder. Yet another ISP actually realized that copyright had long since run out on the work. That's real scary, don't you think? Made up society, Hotmail addresses and a website is gone.

BOF's paper is available here (PDF)