try to avoid US airline if you can,especially coming back.
but again it all depends on your nationality and gender. in my case (middleastern) and i don't look like anybody that they have any interest in, they still searched me 2 times one time while checking in coming back from Germany and the second one right before i board the plane.
just to make sure i have no bombs or box cutters.
2 funny things happened:
1- they have 2 security men right at the line where you get your boarding pass. one guy is American who speaks German and the other one is Somalian or Ethiopian national who also speaks German an English. first the American guy had my RTD and passed it to the Ethiopian guy and the Ethiopian guy knotted his head and this is when the American guy took me for a good search.I figured that they put that guy there to identify the middleastern names.
2- where did he take me for a search?? right in the hallway about a few steps away from the plane. they laid a blanket on the floor (no kidding) and opened my bags and searched every inch in it. just to make sure everybody that is going on the plane can see me, Even the captain looked at them and said can you please hurry up or you can conduct this somewhere else. Do you have any idea how embarrassing that was to me?
anyways, i learned my lesson and decided not to fly overseas on US airlines again or simply wait till i become a citizen and personally i can't wait to become one.
when i came to the US thru Dallas airport, it only took the officer 5 minutes and i was on my way home, no question asked.
Good Luck