Back a few months ago when inspectors were leaving the office with 30 tickets a day there didn't seem to be much pro-active looking for unpermitted activity. I hear these days folks around here are getting a knock on the door if there is a contractor's van outside.
Last year about the only time I ever heard of this is if the "Code enforcment" guys got a call from a neighbor.

Are you out looking?

Every once and awhile, issues like this become an active subject in the building department. I would say most un-permitted activity is reported to us by FPL. When contractors/homeowners contact FPL to arrange disconnect/connection, FPL will generally fire off a call to our office to see if we are aware of the work taking place. On occasion, an FPL meter reader will notify their office of un-permitted work such as apparent new service equipment or things like generator installations.

Right now, our city is cracking down on illegal water use/irrigation and has asked us inspectors to keep an out for violators. Other than that, I don't recall any other "code enforcement" responsibilities ever being placed onto us.

I have been very pleased with my building department over these slow periods. Our building official recognizes these times are good for updating documents and paperwork and implementing cross-training and education opportunities. I have yet been asked to perform "busy work" just to give the appearance of an active building department.

For example, today I managed to get 4 hours of building inspection training hours in and spent some time updating phone numbers and other information on our building department website.

I agree the industry is well served by a chance for the builders and inspectors to catch their breath and look at the operation.
My wife is looking at warranty calls right now to see what they can do better when things start moving again.