Interesting article linked from Bruce Schneier.
They used to rob banks, but banks were hardened. Then they robbed cash-in-transit vans, but the trucks were hardened. Now the tactic is to take a family member hostage and force an employee to do the stealing for them.
This is actually an old trick in Ireland. The IRA would kidnap a child and make the parent drive a car bomb into a government building garage or equivalent, often resulting in the parent's death.
The reason this works in places like Ireland is that while governments, corporations, financial institutions, etc. can harden as much as they want, all civilians are unarmed and thus soft targets. The bad guys attack the soft targets to get to the hard targets.
Yet another unintended consequence the anti-RKBA crown just can't/won't understand. It might work in California or New York or Maryland, but don't bet on it working smoothly in a free state.