This is an FCC fine, not a court-ordered one if it is the FCC that
upheld it. That means they ahve no way to collect it except by
holding up any other FCC licenses or whining to credit bureaus(if they
even do that).

Remeber the Janet Jackson issue? The FCC wanted to fine her,but
soon realized they would be unable to do anything if she refused to
pay as she does not hold any FCC licenses to revoke.

Only court-ordered fines can be imposed using threats of jail
time. I would advise closing bank accounts if you are ducking a
court-ordered fine, but these guys have no more power than a
credit-card company. this fine is like a parking ticket against
someone with no license plates or drivers license, and just as
uncollectable.