When is it Fair Use to Use a Photo to “Illustrate” an Article?

One of the practices that has generated a sizeable number of disputes and rulings is the use of photos to illustrate articles. There is no shortage of articles being generated online, and often those content producers simply canvass the web to find a suitable photo. These three cases address fair use in this context.

A very good article by Venkat Balasubramani on the ever-present question.