"ZOMG PIRACY IS THEFT". It isn't.
Of course it is. It's also frequently murder. But it only really counts if you use a cutlass and wear an eye patch.
In order for something to constitute theft, somebody has to be permanently deprived of property. Not profits, not the possibility of profits. When somebody's deprived of profits, that's not theft, that's copyright infringement.
That's not necessarily true. Many, if not all, states have laws concerning theft of services. I'm not saying that copyright infringement is or is not theft, but I get really annoyed when people keep repeating the incorrect statement that theft must involve loss of physical property.
I am not trying to be a smartass here but what does theft of service actually mean? Is it signing a contract for work done and then not paying? This doesn't sound anything like illegal downloading to me. On the other hand maybe I should become a plumber. Then I can sue all the other ones in my town for theft of services. Obviously if they didn't exist then all their customers would come to me! How dare they take my livelihood!