Basques have a reputation for their fighting skills but the pro-Hamas crowd decided to FAFO anyway.
The Spanish Police are professional and polite but firm. They want you to know they are in charge and not you. F around with them and they will F you up.
I have been to Spain many times and never had a problem. I was always polite and they were always very professional but firm. If you are a foreigner and speak Spanish they are very pleasant. Last time we went to Spain we spoke no English but rarely. We stayed in hotels where middle class Spaniards stay. I speak Spanish and my wife's first language is Spanish which we speak at home a lot. Spain is a great vacation and the food is excellent. Spaniards are very serious about their food!