I asked the stock photo agency (one of the bigger ones) if I could use editorial-only images for this purpose (as my resulting compositions have no branding try to sell something, just create community).
To my surprise they said I couldn't use ANY stock photos (i.e. even non-editorials) for this purpose, and listed their prohibitions.
None of those prohibitions applied so I asked them to point out which one I would be in breach of and they have not responded.
Anyone got any general insight here?