But I think that's the whole point. This is a storage place in the Meat and maybe keeps physical worth or secret things that can't be accessed and downloaded from the Matrix. It would be guarded, fortified but still inconspicuous, and the contents almost eerily secret, ALL in the Meat.
So, essentially a vault full of artwork, valuable antiques, gold, gemstones, offline backups of blackmail files, and other such negotiable trade-goods which would still require a place to physically store them?
I'd say definitely either deep underground or in orbit, first off. Probably underground, since you want Gringots. Secondly... many, many redundant sets of massive, hardened bank-vault style doors that only open in "airlock" sequences (aka, they won't open the next until the one behind you is closed), and a severely high level of sensor presence, not even counting the Security Checkpoints, with it all hard-wired and the WiFi access permanently removed on a hardware level.
Oh, yes, and don't forget Turrets with Mk 74 Smartlinks, all running Pilot 6, Targeting 4, and hooked up to a Rating 4 TacNet. At
least 4 per room, and backed by some
very talented, very highly paid, and very well-equipped "live" security, also subscribed to the TacNet.
All WiFi access points are on 24-Hour Strong Encryption (if not Plot Encryption) running at Rating 10, and there's multiple Spiders present for each shift, backed by an infinite number of Agents (aka, an Agent Program with no Copy Protection), and a complete suite of fully Optioned Rating 10 Programs.
Magically, we're looking at
at least one significantly Initiated Magician per shift, Wards, widespread use of telltales, and the constant presence of multiple high-force Spirits on patrol.
Not a "fun" place to break into, but that's rather the point. Banks, especially high-profile places like Gringotts, don't mess around with the security of their secure storage.
Of course, if a group can pull it off they'll have gotten enough money to not only buy a SIN and retire to a Luxury Lifestyle, but probably also buy enough stake in a AAA to get a seat on the Board of Directors... or at least a personal invitation to major social events.
That is, of course, assuming they live to spend it, that is, since the Corporate policy of "cut your losses" doesn't apply to a place whose reputation for security is their main asset.