No fly list is unconstitutional, and without Due Process. Hard to get off the list, and some dont know there on it.
I heard on the radio, it may include veterans, people who visit psychiatrist, depressed people, some who visit these type of sites. SO Frankly Anyone.
I may go to buy a 22 and be told I cant and they dont know why. Then get a Knock later saying I have a Warrant to confiscate the firearms here.