[After a brisk nap]

Besides, I don't think the example Melanie referenced does state that copyright infringement is theft. All I see is that the description of the penalties for criminal copyright infringement (the most serious kind, not your everyday piracy) have been put in a section called "Stolen Property", along with a bunch of other crimes, not all of which we'd call "theft". The description of the crime itself is not under this section. Any conclusion that "copyright infringement is theft" can only be inferred, as no such thing is explicitly stated.

Also, if by "theft" we mean larceny, and we usually do, then copyright infringement is definitely not it. Larceny involves an intent to deprive the owner of his property. At most copyright infringement might be considered a case of criminal conversion.