The only thing they're worried about is whether or not your juice and tank are in the clear baggie with your other liquids, and whether your juice bottles fall under the 3oz rule. And, as Rwb1500 said, if you have batteries they need to all be in your carry on. I've flown several times since I started vaping. I put my juice in my baggie with my toothpaste and toiletries, and my mods in my carryon inner pocket. TSA never batted an eye, asked a question, or looked twice at the xray. E-cigs aren't new, they know what they are. They're worried about other stuff than vape gear.