I've never had a problem bringing a Provari or mechanical mechs through airport security. I put my mods in a case that goes in a bin with my keys, phone, wallet, etc. I keep my batteries in my carryon, and my liquid in bottles (less than 100ml) in my quart ziplock with my bottles of toiletries. Only once did someone ask me about my mods - he was familiar with electronic cigarettes but had never seen anything like mine (he was personally curious).