[superuser2]

An armed assault on Coinbase HQ while staff are present would be a nearly foolproof way to instantly, irreversibly, untraceably obtain a few hundred million dollars of BTC.

Its physical security requirements would be orders of magnitude beyond any other SV startups, even greater than the largest banks (because banks can retroactively reverse transfers and call the police when you try to deposit suitcases of stolen cash). We're talking Federal Government-level security or better, because even US military facilities in the U.S. assume their threats are enemy states, which would have to get through the Navy and Air Force first. We're talking something much closer to an onsite, 24x7 paramilitary force than a guy at a desk in the lobby.

Keeping a low profile would be a good place to start.

Hopefully there are other controls - cold storage can only be accessed by a quorum of people which never under any circumstances exists in one location, etc.

Expecting to ever see inside of Coinbase's HQ is entirely unreasonable, IMO.

[MichaelGG]

If you're thinking that way, then an attacker could also just kidnap/torture relatives of key people. That's far lower key than an assault on an office building with cameras, silent alarms, etc.

[superuser2]

It's not that hard to design internal controls that prevent a few compromised individuals from stealing too much.

It is that hard to design internal controls that prevent a theft when 100% of the staff are in the same room with their computers and guns to all of their heads.

[krupan]

Untraceably? Surely there are at least a couple security cameras in their office.

[beaner]

And also this thing called the blockchain.

[chiph]

We're talking something much closer to an onsite, 24x7 paramilitary force

There's a reason why the United States Bullion Depository is on an Army base. (James Bond plots not withstanding)

[rudolf0]

Theoretically, what do you think would happen to the Bitcoin market if their entire hot and cold wallet were stolen at once? Would the value crash to the tens of dollars?

I'm not sure the thieves would be able to significantly profit off of their heist if they took everything at once.