The protests are in part (motivated by the NUS) political. Such action would have been welcome over the past 13 years under which Labour introduced tuition fees, then top up fees restructured the student loans system, effectively abolished student grants and privatised the Student Loans Agency.
The NUS were protesting against fees during the Labour years.
The NUS support tuition fees. Well, atleast that's what Aaron Porter, union president, said on Newsnight on Wednesday. Any NUS members who aren't happy about that should surely just leave the union.
They changed their policy a few years back; they were against them altogether. The Lib Dem promise to abolish fees garnered them a lot of student votes and swung some seats (Rochdale in 2005, oddly held by a former NUS President, for example).