Spain is like the big refuge country for the crème de la crème of European organized crime. There's crews from the former Soviet Union (Georgians, Russians, Armenians, Azerbaijanis, Jews from Russia/Ukraine/Belarus/Moldova, Chechens...), Italian crime syndicates (Sicilian mafia, Camorra, Ndrangheta...), Balkan groups (Serbs/Montenegrins, Albanians...), Turkish groups (traditional Black Sea mobs as well as Kurdish clans)...as well as criminal firms from the UK and Ireland (firms from Liverpool, the Southeast, Dublin, Glasgow, Nottingham...), the Netherlands (Dutch 'Kampers', Moroccans, Antilleans, bikers...even old school criminals) and France (French Algerians, Moroccans as well as Corsicans...) all arriving in the country. An assload of money is laundered by gangsters from all of those places in Spain. Inter-gang feuds are being increasingly handled in Spain as well; not a month goes by before another Irishman, Moroccan, Georgian...gets whacked.

Spain always had this reputation really. It might not be known for being a specific breeding ground for organized crime itself, but it's a relative comfort zone for crooks throughout Europe.