Students From Wealthy Families to Pay Higher Tuition

According to a story by Steve Sexton reporting for The Washington Times,

The Board of Regents of the University of California examined a proposal for a surcharge on wealthy students at a meeting Thursday. The university would be the first in the country to target wealthy students with a surcharge.

The proposed fee would force undergraduate students with family incomes exceeding $90,000 to pay as much as $3,000 more to attend one of the university's nine campuses. It is expected to affect 58,194 of the university's 160,000 undergraduate students.

Boy, this is right out of Marx's Communist Manifesto. My question is, how would they know what a person's wealth is? Also, if they are able to implement this ludicrous idea, what prevents the imposition of a $100,000 surcharge?