> It's about the ubiquity in fiction. If every police box in fiction was a time machine, it stands to reason someone may be confused when encountering a real police box for the first time.

This is the silliest thing I've ever heard, and not every fictional red cross symbol is a threat anyway. This whole thing seems at least as ridiculous as the moral panic about violent video games in the early 2000s, except that I kind of expect ridiculous moral panics from conservative parents not so much from the official communications arm of one of the largest NGOs in the world. Absent any actual evidence I think we're just going to have to agree to disagree.