It is surprising that as a writer you engage in this misleading usage of the English language. People copying files without your consent may be financially inconvenient for you, in bad taste, even illegal in some jurisdictions, and definitely an ass move. But it is not stealing. You can firmly condemn this behavior without using metaphors.
Nevertheless historical usage includes, "stealing someone's idea", etc. which is as least an applicable sense.
Illegal copying is not stealing. Sad to see this narrative won in the end, I thought we were past this. I though we -- the users -- had won.
If it was only that, it may be somewhat justified. But in this case the "thief" is not making any profit from the stuff he has "stolen", he has just given away a copy to another person. The correct verb in this case is "sharing".
I refuse to partake in the orwellian newspeak of using the verb "stealing" for the act of sharing. This is a hill I'm happy to die on.
Meanings change over time.
One can argue all they want about whether IP laws should exist, but as it stands right now (in re. to language and the law) it’s stealing.