A person who enters a thrift store with full intent to shoplift any items that will fit in their pockets and purses. They may even steal a purse and put stuff in it.
A low form of shoplifter who will go into any store and steal the floor tiles if they're not tacked down well enough.
1. "Did you see that girl in Electronics? She was putting a surge protector in her purse! WTF? She'd be a thrift store robber, that one."
2. Stacy was kicked out of the thrift shop for stealing all the clothes instead of putting them away; what a thrift store robber.
When you go into a Neiman Marcus, Nordstrom or Marc Jacobs and there are $50 tank tops stretched and faded, and generally looking like they came out of a pile of salvation army clothes. you are think WTF? but other people are eagerly trying them on and buying them, even though if you were to suggest they go to an actual thrift store and get the same clothes for $1.99, they would be shocked/horrified/appalled.
That $200 faded black hoodie with the intentional silverpaint splotches is so thrift store chic.
What you tell your significant other what you're doing with an attractive person while you're actually cheating on your significant other, taking pictures of it, and secretly laughing at your idiot significant other for being such a trusting idiot.