yeah, I figured if you can vape liquid nicotine, they'll probably be vaping liquid THC, hence my question. But you're right, "...you'll never stop that type of thing from happening..."
You can also role marijuana into a joint using a wrapping paper meant for tobacco. You can smoke it out of a shisha provided you mix it with some shisha tobacco, you can smoke if out of a .... bade from a soada can, tin foil, a bic pen, an apple, or any number of items that can be used to fasion a ..... And failing that that you can always make a pipe from clay, wood, or metal.
Not only that, but crystal .... can be made from cold medicine, laundry detergant and some other ingrediants availible at your local hardware/convinient store.
Addoral and Riddelin, two perscription drugs given to every hyper active child who can't pay attention in math class, can be ground up and snorted like cocain.
A bomb can be made from fertalizer and sugar.
Thermite, an incindiary that was popular in fire bombs before napalm, can be made from ruse and ground aluminum powder.
Gasoline, a very popular fuel in devices known as "cars" can be used to burn down entire buildings.
A gun can be made from a pipe, a spring, and afew odd bits of metal.
And failing that you could always bludgeon somone to death with said pipe, or purchase a golf club, baseball bat, or kitchen knife and kill somone with that. And if you take martial arts or are just really big and nasty you don't even need a weapon.
My point? You can use any object for nefarious and illegal purposes. Hell, prisoners figure out ways to turn tooth brushes into weapons. Now, some are obviousely worse than others, and it is ridiculouse to say "well, since you could concivably burn down an entire city with a single trip to the home depot we might as well let the public purchase anthrax, napalm, and enritched uranium."
But for items that do have legitamet uses other than illegal drug use, murder, or terrorism then I think the rational thing to say is "OK, it's legal, but if you are caught using it the wrong way you will be charged as if you had drug paraphanialia, and illeagal weapon, etc... and we are going to to still have that list at the drug store so we can keep an eye on anyone buying 50 packs of psuefed a week, and if the guy at home depot sees you buying a truckload of fertalizer, it might be a decent idea to make sure you are a landscaping contractor or something like that."
Make sense? If somone uses an E-cig for a THC juice or any other illegal drug then it will be comphiscated as drug paraphanalia, and any fines or consequences (such as being kicked out of dorms in college) for such paraphanalia will be leveraged. If you just have nic juice, it's just like a cigarette, cigar, tobbaco pipe, or whatever.