How to Cite Maps Used in School/Journalism

Village Soup/Knox County (ME) Times has an article about a proposed plan for Rockland Harbor. The article includes a map, apparently taken from MapQuest, and enhanced (it’s a screen capture; it does not use the API). Below is this caption:

A map of O’Hara Corporation’s proposed project site in Rockland. (Photo by MapQuest.com)

I’m sure that was a cut and paste error, but I do have a point. As more citizen journalism and more students use the Web to search for and use content, they (and others) need guidance in how to cite such references. Let’s assume the map was used under “fair use” (I’m not sure it was). How is it to be cited? Must it include the copyright info for the data? (It does not.) Must it include a link? What do Manuals of Style say? What does MapQuest say?