No. It was more like they were looking to see if there were any outtanding warrants for our arrest or anything rather than if our paperwork was in order or up to date.
We were walking down the calle Preciados and the cops were already standing there doing something else and only stopped us when we were right next to them and it was really convenient for them. When they were finished with us I saw two guys who were much more suspicious looking than us and they did not even look at them. I am pretty sure that this new measure will not be very effective for the people it is meant to catch and only be a thorn in the side of normal people who always cooperate.
From what I can tel it is just better to avoid eye contact with the police and not to speak in English where they can overhear you.
They take advantage of everyone's good nature and mistaken idea that everything will go well if you cooperate, when it is just best to avoid them all together or even disengage like what Mariposita uses to diffuse her arguments. It is not likely that they will chase you down the street if you authentically pretend you did not see them and continue on your way. Remember that no good can come of being stopped or asked for documentation or whatever. So again try to avoid it at all costs, but be prepared and listen very carefully to what they ask you so you only give them what they want and do not volunteer any information that they can and will use against you.