This is some ridiculous pedantry. Theft is a synonym for stealing. Merriam Webster even defines it as the "act of stealing." So if you're going to use "theft of

This is some ridiculous pedantry. Theft is a synonym for stealing. Merriam Webster even defines it as the "act of stealing." So if you're going to use "theft of service" as an acceptable phrase, then "stealing a service" must also work conceptually. To complain that is unacceptable to shorten that to just stealing in a conversation is utterly ludicrous.