On our first visit to Spain after purchasing, our agent spoke to us about the security. We thought it was pretty safe because of the shutters, especially when they are down. Or agent then proceded to give us a demonstation of how easy it was to remove a window or patio door, with the shutters down and minimum of noise!! Window locks fitted the next day.
We were also told that cash is the main object of thefts as it is “personless”. What I mean is that if someone is caught with your passport or credit cards, they are bang to rights. If however you have a pocket full of cash, it is difficult to prove you are not its’ lawful owner.