Definition - What does Piracy mean?
Piracy is a criminal activity that is prohibited by U.S. maritime law as well as international law. It includes but is not limited to violent attacks on ships in international waters.
This sort of crime is carried out by perpetrators aboard non-commercial craft for personal gain.
Justipedia explains Piracy
Modern pirates ply their trade in the waters off the coast of Africa, Central America, South East Asia, in the Mediterranean, and on the Danube River. They are often well armed, well equipped and well organized. Their most frequent targets are commercial vessels, which carry valuable goods. In some cases, pirates specifically target ships in order to capture and hold the crews for ransom.