Are wrenches single-use, or are you allocating individual attackers per-citizen? In the case of a successful wrench attacker, how are the stolen funds recovered?
This is the classic time-money tradeoff. Theoretically you only need one wrench and one attacker—but even if she attacks 100 people a day it would take thousands of years to reach everyone. And word of the attacks would spread, so later victims would take steps to safeguard their money and the attacks would become ineffective.
To be maximally effective you'd need to mobilize enough attackers and enough windowless white vans to reach the entire populace within probably a day, so let's say 3 million attackers and 3 million white vans. That's when things start getting more expensive than the sql query.
that is assuming every citizen has a crypto wallet, something is not even close to be true..
i would guess that percentage of people with wallets would be very small and a relative small team could with a relative small number of white vans and wrenches could get every single one in relative short time..
and for countries that heavily monitor internet usage, like china, i bet they could have a list with pretty good assumptions on who has crypto that they can target for further investigation before sending the wrenched goons..
To be maximally effective you'd need to mobilize enough attackers and enough windowless white vans to reach the entire populace within probably a day, so let's say 3 million attackers and 3 million white vans. That's when things start getting more expensive than the sql query.