TSA knows about e-cigs, batteries and e-liquids. Keep the liquids less than 50ml and in a plastic bag. Keep Li-ion batteries stored so they can't short each other out. I've had no problems with vaping stuff and TSA. Just don't try to vape in the TSA secured area of an airport unless you are hiding in a restroom stall and don't vape at all on an airplane. Carry smokeless tobacco on long flights if you must... you can't vape on these.