Man, I hate this crap. People that work behind the counter at Kinkos and Walmart do not understand copyright law and they are not well equiped to make spot judgements about what is and is not illegal. The result is that copyright enforcement consists of "I think you look like a punk kid so I'm not going to copy this." As a rule, I don't use Kinkos anymore because everytime I go in there I have some busybody trying to prevent me from doing business with them.
The absolute most annoying case was when I was required (by law) to make color photocopies of a government ID and the idiot at Kinkos insisted that I was commiting a crime and threatened to call the police.
There is a fundamental policy flaw in this, but I'm not sure where to pin it. The government has never required cash register clerks at these outlets to act as judge, jury, and executioner for copyright law. These companies have gotten sued by copyright owners who were not satisfied with actually suing the person who violated their copyright, but wanted to go after someone with big pockets (very honorable, indeed). The companies settled, partially because its cheaper then a suit, and partially because they didn't have the forsight to go through with a suit.
There ought to be a law which limits the liability of printing services.
I used to work at a kinkos. One time I saw someone I work with literally screaming at a deaf mute at a kodak kiosk over a copyright issue (it was highly amusing). Most printing places do have copyright wavers which the client may sign stating that they have permission to copy whatever it is. However, most counter people at print shops and such REALLY hate their jobs and the company they work for. If there is anything they can do to keep you from coming back without getting fired, they will.