I worked in the Federal Gov for 20 years. Haha. I'm sure that came across wrong :)

That said, by the time I left, I had enough experience  and seniority in various financial aspects of the fed gov to know how I would deal with the archaic systems that don't allow for easy "stop payments" on a case by case basis. In fact, much of the system is still very manual. That means that if I wanted to limit payments to say a certain type of defense contractors in a region, I would simply call the DFAS that services that area and tell them to suspend approvals in MOCAS (or one of the many other redundant systems we used for payment processing). Would it be a pain in the ass? Sure. Is it possible without too much trouble? Asolutely.  They tell us it's not possible purely as a scare tactic. We've seen them selectively shut down the Gov on multiple occassions just in the last couple of decades. I was working for the American DoD in Australia in 2012/13 when the American Gov shut down. Did they still pay for my hotel room? Of course.  Almost hilariously, because I was a Federal employee at the time, even though they were paying my hotel room and per diem in Australia, I wasn't allowed to go to work until the shutdown was over....and it was strict orders...no fudging / free work allowed by patriots allowed for any reason. Lol - I wasn't exactly upset about that, nor was my new Aussie girlfriend at the time!!