From the iTunes Store Terms of Service, section 9:
(viii) You may not use Products as a musical “ringer” in connection with phone calls.
There’s no way to enforce this restriction with DRM-free iTunes Plus tracks, of course. Anyone know if this EULA restriction is new?
Update: It’s new. Here’s Google’s cache of the previous iTunes Store terms, which contain no mention of phone ringers.
★ Wednesday, 30 May 2007