A counterfeit good is one that has been fraudulently imitated. The definition does not take any quality differences into account, so this aspect is irrelevant when defining counterfeit. It also implies that if a high enough quality can be reached by the counterfeiter then it is no longer considered counterfeiting, which is wrong.
As an example, if I manufacture a pair of shoes and sell those shoes to someone, who then takes them and manufactures 10 exact replicas of the shoes and makes them available for free, then he is clearly a counterfeiter. The people who acquire those 10 copies have not stolen anything. They have acquired counterfeited goods.
Let's also say the copies of the shoes are so well done that they are indistinguishable from my originals. In this case, they can only be identified as counterfeit by identifying the source of each pair of shoes. If they are from an unauthorised source, then they are counterfeits.
Likewise, if you replace the shoes with a MP3 file. If I record a song and make it available for sale, someone buys it and then makes 10 copies to other people, he is also a counterfeiter. Those copies are identical to my original, therefore are counterfeit due to where they were sourced. Songs sourced from unauthorised websites are counterfeited goods as well.
The fact that each file copied is indistinguishable from another, means that the only real way to tell whether or not it is a genuine or counterfeit is where the file was sourced.
In reality, counterfeit shoes are not exact replicas and are usually obvious fakes due to the low quality. The nature of copying a computer file allows a copy to be completely identical to the original. This applies both to authorised copies and unauthorised copies. This is simply the nature of the medium of computer files.
If two items are completely indistinguishable from each other, and one of them is an unauthorised copy, then it is by definition a counterfeit.
So, are unauthorised downloads counterfeit gods? The answer is yes.
People don't respect lies. Hyped up deceptive rhetoric like equating piracy with theft might garner political support for intellectual property rights but anyone who thinks objective will notice it just doesn't work the same way theft does. It works the same way counterfeiting does. If you want to launch a campaign acknowledging that and talking about why counterfeiting is wrong then do that.
Regardless of whatever value is lost or what kind file or software is pirated, the original owner still has the original, while the pirate merely has a copy. Thus, it would only be theft if the original file was deleted or made inaccessible in some way. Calling Internet piracy theft or stealing keeps us from having legitimate debates about it, since most people automatically think stealing is wrong.
While I recognize that internet piracy is not exactly theft, it is closer to that than to counterfeiting. If you give someone a counterfeited product, e.G. A counterfeit $20 bill, you are not giving them an actual $20 bill that holds value, you are giving them a worthless imitation. Someone who downloads a movie does not receive a counterfeit, "sweded" copy of the movie, he receives an actual copy of it. In essence, the parallel to theft is drawn because the downloader's end result is the same as if he had actually stolen the movie. He has paid nothing, and receives the movie. Again, I understand that every download of a movie is not a lost sale, and is therefore not straight theft, but the fact that an actual product is received makes piracy vastly different than counterfeiting.
Equating Internet piracy with either counterfeiting, or theft does not seem quite right to me. It is overall in it's own little category. They call it theft to get us to shy away from doing it, because stealing is wrong, and we see that everywhere. However, counterfeiting does not seem right either. Most piracy done over the Internet is downloading a movie someone else put up for free (when they should not have) the person downloading it did not create it or counterfeit it though, it is still that same movie or file or whatever it is they are downloading.