"Last night's demonstration was definitely different," says the BBC's Tom Burridge, reporting from Madrid.
The protestors were trying to surround parliament, in a protest against the political system as a whole in the country. Social media sites tipped police off that the protest would happen, and they blocked off roads leading to parliament before trying to break the crowd up.
Meanwhile, the Spanish government is still yet to ask for a bailout from its European partners.
"The thinking of analysts," says Burridge, "is that the longer Spain delays this decision, then actually the markets might start to lose confidence. And Spain might then be forced to ask for that second bailout."