I'm taking my new Ego Mega Dual Coil Carto to Lowes an a little while. On the large 750 mah battery this thing is Huge, no way anyone can mistake this for cigarettes or commonly recognizable illegal drugs. I use my Riva in Lowes all the time ( with regular cartos/atty's) and no one has ever said anything to me about using it even though their official policy has banned the use of them on the property.
Why use them in Lowes if I know they are officially banned? Because it's not posted anywhere on the outside of the building, or inside the building. There is no legal binding publicly displayed document saying they are banned.
I believe the "ban" is actually a good thing and it has worked in reverse. Employees now know what the E-cig is and they don't care knowing it doesn't harm other people or stink up the place.