That language reason is a several problem between those regions and the other regions of Spain. Those regions, developed in the past century feelings of Nationalism and Independentism and, with those feelings, born groups defended their rights. Some of them pacific (political parties) and some of them violent (terrorist groups)
In Galicia, both of those problems are present. Pacifically, parties such as Bloque Nacionalista Galego or BNG are trying to change the status of Galicia to be an independent country or a part of Portugal in some cases.
Violently, there is not a dangerous terrorist group as ETA in Euskadi, but there are group of nationalist people attacking to civilian people speaking spanish. Those groups are impossible to recognise, except in a case: Riazor Blues
The Riazor Blues is a fan group of the soccer team R.C. Deportivo de La Coruña who supports the Galician Nationalism and vinculed Galician Nationalism with Deportivo de La Coruña. But, how do they attack?
Here is the scared or funny stuff:
If our team lost, they go in groups of 10-20 people and they ask to any person they find in the streets: "What country are you from?"
If the answer is Spain, obviosuly they will fight you until you got to go to the hospital. If you find them, the right answer to evite those fights is "I'm from Galicia"
Personally, i know too some people against those nationalist ideas and they are receiving amenaces and people is trying to hit them because they think Galicia is a part of Spain.
From here, i just ask to people for tolerance and to respect the different opinions. Don't go back to dictatorship ideals
So i think this is a very important issue in Galicia. And I was talking about the North, were Nationalism are low. Going to the South, nationalists number grows up until being the majority.
(With this blog i dont want to offend to anybody. It is just one of a lot of problems in the city i live and i want to share them with everybody. Next time I'll talk about Bnet and 1.15 ^^)