Any CCTV system that's air-gapped from the internet (records to local storage only) reasonably meets this definition. Yes, there are possible exfil paths, but

Any CCTV system that's air-gapped from the internet (records to local storage only) reasonably meets this definition. Yes, there are possible exfil paths, but not ones that can reasonably be executed on a large scale. Realistically, the danger from break-in and hard drive theft (or warrant/subpoena) is greater for the average user.