I have a website about tourist attractions all around the world and we use automatic geolocation based searches in Flickr/Panoramio/Foursquare/500px photo bases using their public APIs. To filter out private data we use mandatory parameter "public only".
So, the question is: is it legal to display such search results on our pages or not? Say, in accordance with the terms of Flickr (http://www.flickr.com/services/api/tos/) and Panoramio (http://www.panoramio.com/api/data/terms.html) API usage -- any person or company that uses its API can use the images found by it in non-commercial goal while linking back to Flickr/Panoramio.
If your answer is "no" then why and how do Google, Yahoo and other search engines display search results in services like Google Images? And Facebook and other social networks displays such images in Share posts?