I've been seeing this a lot more since 2008, once all the price increases began.
I see lots of vehicles that have a pack-in missing the pack-in now, and sets like the one that features Cad Bane I've seen missing Bane now since he's the "draw" for that set.
That one though, that's pathetic.
My local KM was routinely getting hit by someone doing figure swapping though, and that really pissed me off to the point I took it to the front desk... They were actually really cool about it too, and were surprised at someone even thinking about stealing an action figure. It never even dawned on them that anyone would give a hoot and they just figured they were taking an opened toy back.
To this day (I didn't take this one back, but should) there is a COmmander Cody figure from TCW, but has the Vintage AT-AT Commander stuck in there (no rifle, but completely otherwise). Go figure.
It's a shame... If you can't afford to collect, quit collecting. Don't be a dick. Buy food instead, and focus less on little plastic men.