People don't appear to realise that airfields, while notionally uncontrolled are actually subject to quite a lot of surveillance
You have no idea how much !! Last month I got a visit at my ****ty little grass strip by the "ports police" who are regular police officers seconded to do port protection. they said they were looking for folks involved in terrorism, drug and people smuggling, and have a program running called Operation Pegasus (If I rememberer correctly) which is aimed at making the GA community aware of what types of suspicious activity look like and how to report it. I could tell from talking to them they take their job and the subject very seriously and it was not some kind of make-work project to avoid real work.