I think the same thing has happened here.
I don't use the cercanias trains but I do travel by metro everyday, and I saw a lot more security during the weeks/months after March 11. There were more police officers and security guards walking around the metro stations doing things like looking in trash cans to make sure there was nothing suspicious and occasionaly asking people to open their backpacks, as well as riding in the actual trains. They were also all wearing bright orange vests for a short period of time--I guess to make it easier to find them if you had a problem.
However, the orange vests have now disappeared along with a lot of the security guards, and things seem to be pretty much back to the way it was before the terrorist attack.