Excessive fines clause is a clause of the Eighth Amendment to the U.S. Constitution which prohibits the imposition of excessive fines. Excessive fines clause limits the government's power to extract payments, whether in cash or in kind, as punishment for an offense. The touchstone of the constitutional inquiry under the excessive fines clause is the principle of proportionality. The amount of the forfeiture must bear some relationship to the gravity of the offense that it is designed to punish.
A punitive forfeiture violates the excessive fines clause if it is grossly disproportional to the gravity of a defendant's offense.
One may in theory use this as an argument in a U.S Court I'm not sure however folks are probably not educated about this law.