My first gun, a TM M16A2, was opened up by customs.
The rear tabs were sitting on the OUTSIDE of the receiver. The "C" clip that attaches the inner barrel to the hop up? It was loose in the box. I didn't notice until a couple of weeks later at my first scrim that both my Hop-up rubber and C-clip were missing (fortunately, I found em in the box). Pricks.
On top of that... My first GBB had a mag full of gas... Right out of the box. Retailer never used it. Go customs.
So yeah... Assholes.