Also, the constitution does not mention the right to parody. It doesn't even exist in the section of US code describing fair use (17 USC 107), just in the history of case law surrounding fair use. Parody gets interpreted by the courts as part of the test to determine fair use, and not always in favor of the parodist.
We are, of course, talking to our lawyer about all this stuff. Readers have referred us to many sources in an effort to clarify our position legally, sites like Chilling Effects act as clearing houses for data useful in situations such as this. Also, interesting cases have been brought to our attention - for example, Aqua’s song “Barbie Girl” was contested by Mattel, and Aqua still came out on top (as it were). In darker news, Matt from MacHall send this interesting bit - check page 3, “Dr. Seuss Enterprises Vs. Penguin Books.” To my mind, that precedent doesn’t mean anything good for us.
(sorry, couldn't resist)
It's also not free as in GnuBeer either, since as a general rule they generously decline to explain the reverses in policy (pet theory: it is based on the retrograde motion of Sirius the dogstar, since Apple is clearly controlled by the reptillian lizard-people from there)