At least there is mention of other methods that can be used for the same thing... Any of VST/SmartDisk's thin drives can do the same thing, and cost less money.
If inCompUSA has such lack of security to allow this kind of thing to happen, then they deserve it. Every other Mac store that I have gone to has enough sales people to help you out fairly quickly (witin a minute or two). While at inCompUSA, you can browse their entire Mac selection (I know, sparce at that) and never have someone approach you to assist.
The multi-user suggestion would prevent people from copying, or deleting, items that you need to keep safe. Just set up the accounts as such and leave it logged in as the retail user version.
Just goes to show how many (not all, but close to it) of the CompUSA stores don't have enough people that know how about the Mac.