Minor Employees and Obscenity in the Library

I appreciate your thorough treatment of the topic of pornography in libraries, especially couching it in the larger context of objectionable content. Our library's policies and staff training take a similar approach.

In reviewing our Employee Handbook, our fairly standard Sexual Harassment Policy, and my staff training & orientation on the topic, one trustee raised the question of the library's liability in the case of minors -- specifically, minor employees -- being subjected to viewing pornography in their workplace. The trustee thinks that minors viewing pornography is flat-out illegal, and I don't understand the subject well enough to explain whether it's a civil or criminal liability, or who would be liable in the case of a child glimpsing an adult's perusal of graphic sexual content; or whether we, as employers, should have some kind of parental consent form for minor employees, as we employ Library Pages as young as 14 years old.

Assuming a set of library policies structured as you have previously advised, what, if any, liability does a library have for minors inadvertently viewing adult pornography? And what, if any, modifications to hiring, training, and workplace procedures do you recommend for minor employees?