In Madrid, I read this is what happens:-
SPANISH riot police have fired rubber bullets and baton-charged protesters as thousands rallied near parliament in Madrid in anger at the economic crisis, in clashes that left more than 60 people injured. Riot police in helmets on Tuesday charged to clear thousands of protesters who swamped the Plaza de Neptuno square yelling "Shame!" and "Resign!", addressing the government...Some protesters earlier tried to break down metal barriers protecting the lower house of parliament, the Congress of Deputies, prompting police to chase and beat them and haul several into vans.
A BBC correspondent opined
The heavy-handed tactics of the Spanish police, with little provocation, perhaps show that the authorities were worried that this could have escalated.