Kinkos was in fact successfully sued for just this thing. Example: http://www.bc.edu/bc_org/avp/cas/comm/free_speech/basicbooks...
Kinko's has periodically asserted that it acted at the instruction of the
educational institution, that is, as the agent of the colleges and is without
responsibility. Yet, Kinko's promotional materials belie this contention
particularly because Kinko's takes responsibility for obtaining copyright
permission while touting the expertise of its copyright permissions staff (a
"service [which] is provided at no charge to all Kinko's customers.").
"Copyright Information Letter to Faculty Members," in Kinko's Copyright and
Professor Publishing Handbook, at 40.