From CNN: A series of co-ordinated bomb attacks on Madrid's commuter train system killed at least 186 people and wounded over 1,000 at the height of the city's rush hour. Spanish officials are blaming terrorists from the Basque separatist group ETA for the attack, but so far, there has been no claim of responsibility.

This image comes from a spanish website called El Pais. People seem to be posting it around as a sign of solidarity with the victims.