Requires a law abiding administration.

I can answer this as a serial FOIA litigator.

If the data is still in the possession of the government (e.g. in backups, on paper) then it is FOIA-able.

I had a gov agency temporarily throw all the materials into a trash can when I requested them and argued that since they were sitting in a trash can they were not available under FOIA.

> temporarily throw all the materials into a trash

Just curious, did they pull it out of the trash later on?

Yes. It was argued in court that they couldn't be expected to go into the trash to pull out documents. But they were later. The case was settled on some ground, I can't remember what. Maybe they handed over the documents in the end. This was a decade ago, so I'm hazy on what the final outcome was.

A lot of public bodies will play games like this. It's not even clear to me why they do it. It'll be documents that aren't even controversial that they will resist. Ask them what brand of coffee they buy for the break room and they'll immediately get defensive and find some random exemption to apply. Law enforcement bodies are by far the worst, I think because the public are seen as terminal nuisances all the way down through the bodies.