[pigsonthewing]

The images in this case are copyright-expired (Crown copyright photographs taken before 1 July 1957 = copyright expired 50 years after creation).

Historic England have even stated explicitly "We're not claiming copyright in the RAF images":

https://twitter.com/HistoricEngland/status/15073771987470336...

(they actually were, but stopped doing so once I pointed out the facts to them.)

I know of two further sites where SmartFrame is being used to stop people "stealing" out-of-copyright images, and to label them as protected by copyright.

This is simply a land-grab, attempting to enclose the (digital) commons.

There's also the fact that, for images that do remain in copyright, there are exceptions in law allowing reuse for study, review, parody etc.