As explained, it's an old fashioned bounty on their heads. Govts did this in the days of priacy, hiring private ships and crews to hunt down the pirate ships and kill them and their crews or bring them back home to decorate a ships yardarm.
The Constitution specifically allows the government to issue Letters of Marque for situations where a full military response isn't necessarily appropriate. We have companies in this country that are all former seals, special forces, army rangers etc that make VERY capable mercenaries. Mercenaries to hunt down Mercenaries :)
Godspeed
I don't doubt you for a minute. One thing I am greatly concerned with is another Bill Clinton slithering into office. He could hire mercenaries. In fact, I could envision a Clinton who is loved by soldiers. Most Clintonesque tyrants are more military.
So he hires mercenaries. Well, he would just love to give them some Apache helicopters. Who can blame him? He would just love to give them NSA and CIA contacts. Who can blame him? And he sees an Aspirin Factory that needs bombing. Only this time, it's right inside the US. Not just one aspirin factory, though. He keeps finding more to attack.... Delta would do only so much for this Clinton. Just Waco apparently. Mercenaries would do a lot more for the next Clinton, especially if he is tight in military circles.