Norman,
It sounds like somebody ratted somebody else out to the building inspector. These' guys typically do not have the time or gumption to go looking for corrugated plastic that does not meet code. And I think that the guy trying to solve the problem en masse is not really such a bad idea - it's certainly much more expedient for everyone.
If he were to try to tackle this matter with 56 different homeowners, it will never end, and one guy's porch may be rejected while another is allowed to stand. It'll be monumental. Also, in my area, the property management company is usually responsible for the structure and exterior of the buildings, so it may reallly be an association issue. YMMV.
Best case: Homeowners with enclosures constructed during their ownership have to pay the permit fee, which for something like this can't be more than lunch money.
Worst case: All non-permitted modifications must be removed (at homeowners expense). Those desiring screens must apply for the permit, perform the construction, and have a final inspection.
Real case: Somewhere in between, depending on how nasty the homeowners and the building inspector decide to act with each other.
Advice: Have initial meeting with building inspector attended only by your board. Get a feel for the mood, then approach the populace during your regular business meeting. I guarantee that there will be at least one guy who will scream and yell and bitch and moan about the whole thing. This is the guy that you want to insulate from the building inspector.