I'm developing web-application (and also native iOS app) that uses images from different websites. I can't avoid using these images, so I need to know more about copyright and authorship.
So, the question is: how can I use images from other websites legally? (these images, of course, not from photostocks or other paid-sites). Interested in fashion industry, I need to use images of clothes of famous designers. If I would declare source link to each pic, will it be ok? Or may be use "User Agreement" that tells full list of used sources? For better understanding my question, some examples: websites - news aggregators, blogs and so on.
This is a topic that books have been written about, and law school courses taught about. It's not something you're going to find a definitive answer for here.