I'll add that in the aughts and 2010s if you were sheet white like me, and not an investigative journalist and otherwise had a really boring life it was right and proper to poke at FBI and CIA for profiling people (e.g. Arab American + Muslim = terrorist) by doing behaviors of interest when they shouldn't be surveilling you at all (e.g. in your back yard with their camera drone)
In the International War On Terror are so few true positives (Islamist Terrorists — they didn't care about domestic white power terrorists until 2016) FBI has had to make up terrorists by finding low-intelligence victims that fit their profile and then gaslighting them until they did something terroristy enough to secure a conviction, such as buying some nails for an FBI plant pretending to be a bomb-maker.
So a lot of innocent people are in prison for international terrorism so that FBI could claim to have caught a few.
That said, the watch list and the no-fly list are both bullshit and a miscarriage of justice, since an agent, official or bureaucrat could get you on the lists, restricting your rights for no reason, no due process and there is no reasonable way to get your name off the list.
It used to be a source of NSA words and phrases of interest.
The point was to end all your correspondence with an NSA Haiku to give them more POI false positives since the NSA shouldn't be in the business of spying, but of making spying impossible through robust internet security.