Webster 1913's definition is apt and correct. Piracy is a crime against property, life, and limb. It commonly involves robbery, hijacking, arson, kidnapping and murder. The romantic patch, wooden leg, and parrot image we get from Treasure Island may be irrelevent today (if it ever was), but piracy is still a problem, especially in Southeast Asia.

Piracy is also used as a Newspeak smear word to associate sharing an infinitely renewable resource (usually software) with an actual heinous crime against actual people. It is this kind of dehumanizing that the SPA and the BSA used in their ad campaigns showing "respectable-looking" businessmen or ordinary people, and saying that yes, this is a common criminal, call our hotline and rat them out just like you would any thief or murderer.

Also, piracy is often a misnomer for counterfeiting, particularly music and software, which is a form of fraud.

Do not misuse the word piracy. If you do not like want to say "sharing," you may use the neutral term "illegal copying," or, as Webster 1913 suggests, "copyright infringement."

The Cow--I did read definition three. I found it almost humorous how Webster 1913 editorially introduced it as "quasi-figurative" and "incorrect." If you look at the definition, it deprecates this usage. It's not even a valid metaphor. People get (perhaps rightfully) livid when "rape" is metaphorically bandied about, but at least it is usually a legitimate metaphor. I don't see how marauding and pillaging is at all like copyright infringement. It's a quasi-figurative smear word. And if you know what Newspeak is, you know it has nothing to do with the word being 90 years old and everything to do with doublethink.