Innovation - I find you comments simplistic and deliberately misleading.
You ask above, “... How should we deal with the police running amok and attacking everyone in their sight?”. Ahh, the old loaded question technique. Like asking someone when they stopped beating their wife: the assumption of guilt without evidence. Just so you know, the police don't 'run amok, attacking everyone in their sight' – that particular activity is carried out by violent civilian thugs who make it their business to attend certain protest marches in order to provoke violence. And when these morons are successful in whipping up the crowd into a frenzy, you and others like you, criticise the police for having the audacity to try and stop people from killing them, one another and/or damaging property.
As for your original question as to why the police wear riot gear during violent student protests... are you serious? The police don't wear riot gear during peaceful student protests as has been recently demonstrated up and down the country on countless occasions. The riot gear only comes out when there is a real threat of danger to the police, the public and/or property.