Do you really want TSA going through your luggage, carry on and checked, when you fly? That would add an incredible amount of time to check in.
I was twice "randomly selected" (read: I was nearby when they were finished with whoever they were inspecting) by TSA officials before check-in, who went systematically through my to-be-checked luggage looking for things unspecified. I have also several times received rather serious-looking notes in my checked luggage stating that they had gone through my luggage behind the scenes without my consent. They also demand to see at the very least an x-ray of any carry-on luggage that I take -- including special processing for shoes, anything in my pockets, and the laptop in my bag. The last time I went to the states they took a naked photograph of me with a machine that had "X-ray vision" (though I don't know whether it was Safe Microwave or Cancer-causing X-ray style). Nominally nobody actually saw the photograph, and it identified that my ponytail (I had one at the time) was a Serious Risk worthy of further investigation.
Generally speaking one tries to be several hours early to their flight.
-I've been randomly selected too and questioned. They do this in most countries. It happened for me in Germany as well.
-The notes are a good thing. I'd rather the TSA or whomever tell me when they search my luggage.
-X-raying is probably the most efficient way to search through all luggage going on a flight. It's also been around for a loooong time, way before TSA.
-Shoes is a direct result of the shoebomber incident. I think it's a little silly though.
-You have to empty your pockets/take off belt to go through the metal detector and not set it off.
-The full body scanners are opt out. I have always opted out. Recently that means you get a pat down. Fine with me, given the two choices.
-You sure it was your ponytail?
-Several hours is overkill. 2 at most for international, 1.25 domestic just in case.
I'm not so much objecting to the notes. Rather, I'm saying, "not only did manual inspections of bags happen, they still happen -- just no longer in front of your face." Metal detectors are pretty nice, and probably worth their security, if they were the only factor -- but if they're going to pat you down / naked-photograph you anyway, the metal detector just seems redundant.
Nobody told me that I could opt out of the body scanners, and I was certainly being pushed through them. I am 80% sure that it was my ponytail: I saw the Risky Business circle drawn on a schematic of my torso about my shoulders I felt someone grope between them, and I heard them say, "oh, it's just your ponytail." The other 20% is just because I have no idea what the hell triggered their algorithm or how their algorithm worked or what its false-positive rate.