At least there are lots of Police Departments/Sheriffs that are taking a stance on this. You know it's getting bad when the cops say "no we're not enforcing that"...
So now all the gangsters in Chicago are going to have to register their guns that don't have serial numbers?
Gun bans are impossible. You don't need to bury your AR. You need friends enough with ARs that gun confiscators go look for easier targets. That's how it works in Chicongo. That's why they're bothering you instead.