I'm talking about the scenario where specific individuals who are citizens of the United States have a blanket ban on deposits to their accounts / frozen accounts. This would affect all gateways which provide settlement via ACH or wire transfer. In theory these individuals could do a cash settlement (gold or fiat). Still, there would be a blow to confidence.
This is definitely helpful but the banking cartel could always use government force / regulatory capture to disrupt the smaller banks. Most likely this will be done under the ruse of preventing money laundering, stopping terrorism, or hindering child pornography. A court order might prevent ACH / wire settlements at smaller depository institutions, creating panic and driving the value of those IOUs to zero. The result would be a flight to the "anointed" banks (Goldman Sachs, JP Morgan, etc...)
Technology works both ways. It allows us to be more productive but it also allows those with a monopoly on the use of force to more efficiently extract output from the rest of the world.