I think very few people feel that depriving some person of the fruits of his or her labor in the way that you describe is a moral or ethical thing to do. But, it is by definition not theft. Perhaps some new law, or some changes to law are needed to fairly deal with the problem. Treating it as theft is an abuse of the law.

I think it is interesting that you use a hypothetical author as an example since even before technology showed up and wrecked the party, copyright law arguably failed (or at least was never very good) at its supposed purpose.