National Parks wouldn't disappear (imo)...they would (could?) be transferred off to non-profit corporations. (I think Chimney Rock in NC is set up similar)
Of course, they could also be sold off at a profit. (Anyone want a piece of Mt. Rushmore?)
And I agree with BP on Social Security. It's slowly disappearing anyway. If we continue our present path, SS will grant you enough dollars (by the time I retire) to buy me a hamburger (if I'm lucky).
Where I disagree with liberatians is in governing. Anyone can claim to be a doctor. Be able to buy any drugs. No meat inspections, etc.