It doesn't take much imagination. "Free" doesn't mean there isn't a lot of money swirling around.
Spell it out for me. Exactly how would you scam a free community college?
Usually done by giving an inflated contract for services of some sort, to an associate. Associate often returns a kickback to the giver.
As a campus needs a large maintanance budget, this can be a big source of fraud.
However, I agree that low-cost state run colleges are a better strategy than free loans.