I think I have figured out what this means. Maybe someone will confirm.

There is a check-in system for tracking when people enter a location. They have a CR code which people scan on smart phones. Tracking software registers them as at the location.

Is such tracking software mandatory anywhere? Do they require citizens to have smartphones?

In order for this to work and not get caught, you must avoid checking in or being trackable. If you are the last to check in at multiple sabotaged CR code locations, they will know it is you.

OP should have explained.