We were in Barcelona last weekend. When we were walking down from the art museum to plaza Espana there was a large demonstration marching down the street but it was peaceful. Other than that it looked like any other day in Barcelona, loads of tourists totally oblivious to what's going on in the background. There were also a few dozen tv cameras and reporters outside of the main government offices like they were expecting something to happen but nothing did.
If I were in charge of Catalonia I would have a plan ready that would wipe out every record of every citizen if I even thought Madrid was stepping in to take over. Store a copy of the records somewhere safe in case they let you back in but leave nothing to the new leaders. Every tax record, every traffic ticket, every government transaction with the citizens. If they want to take over let them start from scratch and deal with the resulting chaos.
They would just walk into every home and demand to see all financial records.