Artistic license - any ship which shows up as "wanted" will suffice (if you're pledged in power play, that might be different, but I think power enemies have a slightly different tag).
Strictly speaking, "wanted" denotes a ship that has a bounty in the current jurisdiction. For NPCs, that counts as "pirate" in the eyes of the law (i.e. whoever lays a claim to the piece of space you are in at the moment). Note that
a) that status can change from place to place, especially if you're near a base/station that is not owned by the overall system owner (system owne has jurisdiction over free space, station owner has jurisdiction over the area around their station)
b) as a player, you can get a bounty for a parking violation - so, for becoming a "pirate", you don't really need to to employ (or even threaten) violence
In the context of this CG, you can find "wanted" ships in one of the RES (Resource Extraction Site) in the system, possibly at the nav beacon and also possibly in some of the signal sources. In the CG thread, you'll also find locations for some more ...errrmmm... interesting locations. But from your question, I would assume that you're reasonably new to combat in ED, so you might perhaps want to avoid to jump into a HAZ RES....
