As I said before, copying a file doesn't deprive anyone of anything
except a theoretical future purchase. Look at your example: “If you
share a song that someone would have bought…” How could anyone
possibly know whether that person would have bought the song, unless I
share the file with them in the actual record store, while they are on
their way to the cash register?

If copyright infringement were theft, then it would be part of the
criminal code, but it isn't — it has its own special law, because
it's something different. And while it's true that there are financial
damages involved with music downloading and software piracy, that
doesn't make it theft. It's an improper use of something over which
someone has certain rights. But they are not the same as property
rights, no matter how much you would like them to be the same.

But on the theft part, you are just wrong. Nowhere, in any dictionary that I can find, is theft defined as “only physical goods” . Business 101 teaches of opportunity costs and that is exactly what is being stolen in file sharing.

If you share a song that someone would have bought if they hadn’t gotten it for free from you, you are then stealing that money from the rightful copyright holder. This is black letter law. Software Piracy is a crime in every civilized nation in the world but if your definition it were correct it wouldn’t be.

Finally the conclusion of the Supreme Court case you cite is incorrect. Dowling vs the United States did not say that copyright infringement wasn’t theft it said that the result of copyright infringement didn’t create stolen property as defined by the interstate transportation statute. If you go to Wikipedia you can find the relevant passage where Judge Blackmun says

“The section's language clearly contemplates a physical identity between the items unlawfully obtained and those eventually transported, and hence some prior physical taking of the subject goods. Since the statutorily defined property rights of a copyright holder have a character distinct from the possessory interest of the owner of simple “goods, wares, [or] merchandise,” interference with copyright does not easily equate with theft, conversion, or fraud”

So he is clearly referring to one individual statute and the language within that statute not the ideal of legal theft as a whole. He even says “The Section’s language” pointing out that he is specifically talking about that statute.

As I said before, copying a file doesn't deprive anyone of anything
except a theoretical future purchase. Look at your example: “If you
share a song that someone would have bought…” How could anyone
possibly know whether that person would have bought the song, unless I
share the file with them in the actual record store, while they are on
their way to the cash register?

If copyright infringement were theft, then it would be part of the
criminal code, but it isn't — it has its own special law, because
it's something different. And while it's true that there are financial
damages involved with music downloading and software piracy, that
doesn't make it theft. It's an improper use of something over which
someone has certain rights. But they are not the same as property
rights, no matter how much you would like them to be the same.

But on the theft part, you are just wrong. Nowhere, in any dictionary that I can find, is theft defined as “only physical goods” . Business 101 teaches of opportunity costs and that is exactly what is being stolen in file sharing.

If you share a song that someone would have bought if they hadn’t gotten it for free from you, you are then stealing that money from the rightful copyright holder. This is black letter law. Software Piracy is a crime in every civilized nation in the world but if your definition it were correct it wouldn’t be.

Finally the conclusion of the Supreme Court case you cite is incorrect. Dowling vs the United States did not say that copyright infringement wasn’t theft it said that the result of copyright infringement didn’t create stolen property as defined by the interstate transportation statute. If you go to Wikipedia you can find the relevant passage where Judge Blackmun says

“The section's language clearly contemplates a physical identity between the items unlawfully obtained and those eventually transported, and hence some prior physical taking of the subject goods. Since the statutorily defined property rights of a copyright holder have a character distinct from the possessory interest of the owner of simple “goods, wares, [or] merchandise,” interference with copyright does not easily equate with theft, conversion, or fraud”

So he is clearly referring to one individual statute and the language within that statute not the ideal of legal theft as a whole. He even says “The Section’s language” pointing out that he is specifically talking about that statute.

Theft refers specifically to physical goods — since stealing an
actual physical item from you deprives you of the use of that item.
Copying a song deprives no one of anything except a purely theoretical
sale, which might never have occurred in any case — and that's why
the Supreme Court has specifcally said that it isn't theft. It's
copyright infringement, which is something completely different.
Copyright is a balance between the rights of the creator of the
content and the benefit that society as a whole derives from that
content, and it is a constantly shifting target.

As for those articles about file sharing decreasing, those are
inconclusive at best, and in any case they are from three years ago –
surely you can't be arguing that it has been declining since then?
Grokster and Kazaa and others may have declined or been shut down, but
new ones have taken their place — for example, BitTorrent has been
climbing in usage at an almost exponential rate, and now makes up a
substantial portion of all net traffic.

The radio analogy isn't perfect by any means — my point was that the
record industry opposed the compulsory license given to the radio
industry just as it has been opposing file-sharing, and it has made
far more money from radio airplay than it ever could have without it.
I think it would be in the industry's interests to find ways of
working with new technology instead of suing its own customers.