Find an anarchy system, all NPCs will be lawless so you can attack at will without consequences. Find haulers ships either on nav Beacon or on convoy dispersal pattern signals.
What you said is true, but shoting and killing innocent npc haulers in anarchy systems just because they are lawless and there will be no retaliation or punishment upon these actions is quite harsh. Except for pirate role players of course.
The only thing I can imagine is mounting a kill warrant and scan these haulers in anarchy systems prior to attack. If any of them is wanted then ok.
Actually it also works in non-anarchy systems in SC. Finding wanted haulers, interdiction and take that we want. Quite rare though and no guarantee the will drop mc.