I suspect a lot of them are vapers (closet or otherwise) and I typically only get a lot of attention when I have a mod that looks 'cool' to the agent(s) in question. Sometimes it seems they are afraid to really engage in banter about them so they surreptitiously ask about them. As an aside, and a few months late, I must say that my experiences with TSA agents overall has been on the great side of good. If you approach them with understanding, respect, and a smile you slip through quickly. I appreciate their dedication, and the horror that dealing with huge crowds of tired, grumpy, impatient people can be. Its not an easy job, and usually quite thankless. So thanks to any/all TSA who may be able to see this, or people who have family/friends on them. To the rest of us, just smile, be patient, and remember that they stand in the airport and deal with the lines for hours, every single day. Youll get through, and I havent met a single agent who balked at mods/devices or juice, just understand if they want to look at it, and youll be on your way in a minute or less.