Why don't American students riot over tuition costs?

This question is inspired by the link in @cruiser’s question

The protests followed a vote in the House of Commons to approve a plan to raise the existing cap on tuition rates charged by universities from £3,000 to £9,000 a year. In U.S. dollars, that’s a nearly $10,000 a year increase—from roughly $4,700 to $14,000.

That seems like a bargain compared to US universities. Why don’t US college students protest tuition increases? Or debt financing for education?