The free samples scam is nothing new. Me and my buddies who were into electronics in the 80s did that to get free chips, because we just didn't have the moolah to afford them newfangled microcontrollers as teenagers. And I think the chipmakers we called up and asked free samples from weren't exactly fooled either: they knew we were kids and they were happy to oblige.
So yeah, technically it's theft. But I'll tell you what else is theft: selling e-juice. It costs pennies to make gallons of the stuff, and e-juice makers sell it for several dollars per 10ml bottle. That kind of margin... well, there's a scam for you... Scammers getting scammed get no sympathy from me.