I wouldn't really call theft of services "stealing", but I'm not a native speaker. Maybe that's something people say.
> Pirating is theft.
Do you mean copyright violations or ship piracy?
I don't see how this follows, because torrenting a movie doesn't take a service from the movie right holder. They wouldn't even notice if they wouldn't actively monitor torrent users. Theft of service is a crime because it causes unpaid work for the service provider, right? That's why I said the gym analogy doesn't apply here.
I think the idea (which is why i asked the original question) is "theft" of opportunity for income.
Theft of services isn't just about causing unpaid work; it involves intentionally depriving a provider of the rightful compensation for their services.
Both cases are equal in principle.
Theft of IP falls under a different law in the US than theft of something like gym services.