Barbara is right for USA - fair use exists in that country , I'm in Canada and I have to abide by fair dealing that does not permit distribution of print/digital copies for educational purposes unless the creator/copyright holder or a collective representing the copyright holder (ex.: Access Copyright) permits.
If Flickr.com has a mishap with posting for authoship with CC , then FlickrCC would perpetuate this. So I pointed to safe use in Canada : no commercial use or no educational republishing. In Canada ,the fair dealing & educational exceptions would not work if one republishes in digital course modules or print modules photos with uncertain copyright. Maybe one or two can be an honest error, but all from uncertain resources would not fly... Only thing allowed for Cnd:is to project in class (no distribution). We are close to the US border but not close to the legal system, so fair use can not be used....