There was one time when they didn't get away with it. After Doom was sent to Hell in Unthinkable (and messed up Reed's face on the way down), Reed decided to go to Latveria and tear everything down and put himself in charge. (Authoritative Action arc) Nick Fury warned him that SHIELD was going to ordered by the U.S. government (probably the U.N. too but not sure about that) if he didn't step down. After it was all over, Reed and the Fantastic Four corporation had to pay a hefty fine.