If the banks seize Twitter, do they really have to own and operate it? They only need to be able to flip it for at least the value of the $13B liability it collateralized, plus whatever associated legal and tax costs. Twitter is probably not worth $44B anymore but supposing they can seize it before its users and assets and brand have all gone to zero, I imagine that there is someone somewhere who is willing to gamble $13B for the opportunity to own Twitter, pick up the pieces and try to restore their credibility and value prop, and try to take it public with at least a $20B valuation so they can cash out at a nice profit.