Something about this makes me very uneasy: Secret Panel can Put Americans on "kill list". It strikes me as wrong in the same way that secret, warrant-less searches are wrong or that secret laws are wrong. I do not think the government can just arbitrarily suspend the Fifth Amendment when they find it inconvenient. This is not just a liberal concern, many conservatives are also uneasy about this too.
Now let me be clear: I'm sure the people perpetrating this stuff think they are doing the right thing, but these are the kinds of powers that over time can become abused by a government against it's own citizens. The Founding Fathers knew quite a bit about governmental abuse. They put these protections in for a damn good reason.