Just put the PC's in the most visible and busiest part of the library: right near the entrance with the monitors facing the entrance way and front desk.
That's about where they are. Evidently the perv's are still using them.
That won't bother some people - I used to work with a Russian contract programmer who thought nothing of viewing porn in an open work area with women passing by all day. This was at a software company who cared more about getting the project done than about PC imperatives, but people from other cultures are often extraordinarily obtuse about how such actions are perceived in America.
That's just the problem. That people are looking at this stuff in full view. I, for one, welcome the all-or-none stance over the let's-legislate-it-to-death one.
"Just put the PC's in the most visible and busiest part of the library: right near the entrance with the monitors facing the entrance way and front desk."
There are perverts who get off on shocking people. They would go to the porn sites anyway.