Piracy is a controversial term used generally to refer to any activity that makes a profit from the theft of goods.
The first recorded instance of space piracy occurred approximately eight years after the completion of the Lister Mining Station in Jupiter's orbit. A small group of criminals began regular raids on the station after establishing a temporary base on Megaclite. The corporations that owned and operated Lister eventually invested in stronger defences, and the pirates were forced to shut down their operation.
This sequence of events went a long way to setting the precedent for corporations taking responsibility for defending their own assets, rather than relying on the rescources of the Earth States Commonwealth.