The Sime Border Patrol can sometimes be bribed to overlook such offenses, but generally such activity is frowned on because it provokes the Wild Gens to counter-raid, choosing law-abiding citizens as their targets. The Licensing process is to limit the "take" of Wild Gens so they won't move away or be hunted to extinction.
Often Unlicensed Raiders are individuals, or small groups, who cross the border and raid in Gen Territory. They are not sanctioned by the Sime government and usually take a Gen for the Kill, or Kill it where they find it, before returning to Sime Territory. These are the ones the Sime Border Patrol might take bribes from. Other Unlicensed Raiders who organize in larger groups and Raid to collect Wild Gens for the choice auctions or other profitable sale are less tolerated because they can do more damage to the vital resource of Wild Gen communities near the Sime border.
See: Gen Runner