In the UK we have payphones provided by the (not quite government) company BT. They refuse to provide a list of the payphones due to "National security", at first this seems absurd, however it may have been legit years ago.
Presumably there reasoning was if all the phone boxes were public, then the infrastructure behind them and the nations backbones would be public knowledge also, and so an enemy could take a few key point out and take the nation offline.
Nowadays we infrastructure is everywhere and already public knowledge, so I don't think the argument stands up any more. So I plan to release the payphone data.
I'm going to survey all my local ones (that I know about), add as much data as I can, then publish it. It'll be under the ODbL as it's derived from OSM. If the data country wide is good enough I'll publish that too, a few upcoming StreetComplete quests may help improve the data.