Fortunately the TSA has established some guidelines that will *most likely* prevent you from getting tazed next time you go through the security checkpoint (no guarantees).
The TSA guidelines for liquids in general also apply to e-juice:
"You are allowed to bring a quart-sized bag of liquids, aerosols, gels, creams and pastes in your carry-on bag and through the checkpoint. These are limited to travel-sized containers that are 3.4 ounces (100 milliliters) or less per item. Placing these items in the small bag and separating from your carry-on baggage facilitates the screening process. Pack items that are in containers larger than 3.4 ounces or 100 milliliters in checked baggage."
You *MAY NOT* put your vape in your checked luggage. It must be brought with you in your carry-on bag or on your person:
"These devices are prohibited in checked baggage by international regulations and the FAA prohibits carriage in checked baggage. These devices can only be carried in the aircraft cabin (in carry-on baggage or on your person). Please also check your airline's policy as they may place additional restrictions on these devices.
When a carry-on bag is checked at the gate or planeside, all electronic cigarette and vaping devices, along with any spare lithium batteries, must be removed from the bag and should be taken with you in the aircraft cabin."
Lithium-ion batteries (aka those 18650 batteries that most likely power your vape) also have to be brought either on your person or in your carry-on. They can not be placed in your checked luggage.
"You may travel with dry batteries (AA, AAA, C, and D) in your carry-on or checked baggage. The Federal Aviation Administration (FAA) prohibits loose lithium batteries from being transported in checked baggage."
The Department of Transportation has banned vaping on planes (sorry, no stealth vaping allowed) as well as charging your vape on the plane (to prevent a fire hazard.)
Let us know how your travel experience went and if the TSA gave you a hard time about your e-cig!