MY THOUGHTS EXACTLY. THEY WOULD ONLY BE ABLE TO DEFEND AS LONG AS THEY REMAIN SOLVENT PAYING HIGH ENOUGH FEES TO OUTBID ALL OTHER TRANSACTIONS.
NOT LIKE THEY CAN CONTINUALLY PRINT MORE BTC TO PAY FOR THEIR EVER INCREASING FEES.
Discussion
when you have thermodynamic money, trying to find attacks is like trying to violate the law of conservation of energy.