Most legal references to piracy do now also include notes that it can also relate to copyright infringement. However, they are all very clear on that point, they relate to *copyright infringement* not the "theft" or "stealing" of any work, and the reason for that is because copyright infringement is legally not theft or stealing in any sense whatsoever (under UK law along with most jurisdictions at least).
In english law, the definition of theft could not be more clear, and for something to qualify as theft explicitly requires that you deprive the victim of what you steal, exactly as Hossie's handy guide demonstrates.