The ECB (European Central Bank) has imposed "austerity measures" on a number of countries in Europe - most notably Greece - following a considerable debt-crisis that has been ongoing for a number of years. What they are saying is that any country wanting to borrow money from the ECB, in order to cover their financial obligations (and avoid bankruptcy) must comply with a number of "savings measures" prior to having these funds granted to them.
Countries wishing to borrow money from the ECB are, generally, in considerable financial distress. For them there is usually two options - leave the Euro or accept the imposed savings measures. Both aren't easy to communicate to voters, and both will bring a lot of hardship to the citizens of that country.
Especially Germany has been very vocal about imposing harsh savings measures on countries like Greece, as Germany is the main contributor to the European "bail out fund", where the money for these struggling countries comes from. What Germany wants to do is make sure that, if they're going to spend more money on struggling economies, these economies will do their best to get their finances in order.
This has lead to a lot of resentment of German policy in the past years - both from within and outside Germany. Given Germany's Nazi past, far reaching sanction on economically vulnerable countries are tough to defend in the eye of the public.
The ECB has its headquarters in Frankfurt, Germany - the financial capital of mainland Europe, and home to one of the largest stock markets in the world. Yesterday, on Wednesday, 18th of March 2015, the new ECB headquarters got inaugurated by all the leading European bankers. This is an unpopular crowd in some circles in Europe at the moment. This, and the fact that the new ECB headquarters are quite pompous (and cost a lot of money) made some people very angry.
Today around 10.000 protesters, affiliated with the "Blocky" movement started wide-spread protests in Frankfurt, in response to the inauguration. People came from all over Germany, and even as far as Italy and Spain. Unfortunately there's always those cuntbags who take serious political discourse (which may happen in the form of calm, public demonstration) as an excuse for violence and chaos. It is those dickbags you see in the video.
They set on fire multiple cars (police & private), smashed shop windows, blocked streets and injured several people (at least one police man was brought to hospital with serious head trauma after being hit by a brick). The power of words still seems to elude the unenlightened few... fuck 'em.