A great case is the UK Post Code system (which is much more specific than the US zip code system here - no more than 15 letter-boxes share a unique post code in UK).
A number of people have created Post Code to lat/long conversion tables. They're all facts but because they have been worked out they are copyrightable. To stop copying the providers introduce slight variances in the data to track duplication and usually jump on top of it.
An even more unusual UK example would be the "copyright" claimed over the football fixture lists you'll find on any popular sport site - they're supposed to pay a large licensing fee to a company called Football Dataco even if they source the data independently.
