If I remember rightly the rules state something about the fines being up to $10,000 dollars and jail time.
Caveat: It's been a long
time since I let my Advanced Class license lapse, much less since I studied for it. It's been a long
time since I studied for, and passed, my First Class Commercial License class and obtained my Second Class Commercial License, but, IIRC and things haven't changed:
A violation of your FCC license is US$500/day, per violation. N.B.: IIRC: Because of the way the Rules are written and because of your licensing terms, Violating the rules for any class of service is always a violation of any licenses you hold. Violating the terms of any FCC license(s) you hold reflects on all
licenses you hold. All can be suspended or (perhaps permanently) revoked.
No license(s)? Well (and this always comes as a surprise to people): Then they can't fine you under the Rules. Pretty neat, eh? Nope, instead they get you for violating the Communications Act. (Well, it's the Telecommunications Act, now, but I'm an old timer.) That one is, or used to be, a penalty of up to US$10,000 and (or?) a year as a guest of Uncle Sam. It's probably a Pretty Safe Bet that getting nailed for violating this Act will preclude your ever obtaining an FCC license for any service.