They recently busted two audio shops here, and two thieves that were friends of best buy employees. (they, being the cops). The audio shops were just basically taking customers info, and then watching them, and stealing their shit. Customers with alarms, the alarms were disabled, or the horn disconnected before they left the shops.
Pretty shady, but in your case, I'd think about going somewhere like circuit city, where thats ALOT less likely to happen. Also, at circuit city, you can give them a bogus address, etc, just to be safe.