Bug: Google+ People Search API always returns 0 re

Question

Requests to

https://www.googleapis.com/plus/v1/people?query=john+doe&key=[key]&maxResults=50

for whatever ?query always returns zero items[]

{
 "kind": "plus#peopleFeed",
 "etag": "\"ucaTEV-ZanNH5M3SCxYRM0QRw2Y/Zbzi1ZPF4WuKo3Uhmc0kd8tdybA\"",    
 "selfLink": "https://www.googleapis.com/plus/v1/people?query=john+doe&key=[key]&maxResults=50",
 "title": "Google+ People Search Results",
 "nextPageToken": "",
 "items": []
}

This is also the case in the "Try this API" form located at https://developers.google.com/+/web/api/rest/latest/people/search