My biggest gripe is the NAME - why the "H" do they call it a 'gun BUY BACK' ....?   As if they had sold us the guns in the first place.  BS.  I really do NOT like providing these barstages any publicity - but then, draining THEIR resources by having them buy junk is poetic justice.
Sadly, the rabid antis have figured it out in many places - nowadays locally they just give out coupons to local stores - WalMart and Target mostly.  "Sell a gun, get a pair of cheap Chinese sneakers!"  
Another peave is, they don't do legal transfers.  If I give them a gun, they'd darned well better sign a Form 4473 so I can prove I no longer have this gun - just in case it gets used for nefarious purposes later - this is especially important for those who live in Socialist cities and have to have nonsense like 'permits' and 'FOID cards'.