That's an interesting position to be in. If you're legit now but you have some past event which might be uncovered, do you approach the DOJ (through a lawyer, of course) to turn yourself in and try to cut a deal, maybe probation and free consulting services for TLAs for a few years, or do you just hope it never comes to light?

Then again, any deal probably means informing on friends and acquaintances of that period and scene. You could try to contact some of them and see if you could go forward together, but then you're setting yourself up for a prisoner's dilemma situation.