[MichaelGG]

I believe nowadays "piracy" isn't being used as a metaphor at all, it's just a re-purposing of a word. No one is conflating the act of sea robbery with copyright infringement. No one is saying "Our navies need more funding because of these pirates." With "theft", there's no metaphor being used. It's trying to set things up to use theft as a synonym for copyright infringement.