"When she signed up for a career as a school librarian, MaryAnne Coppersmith never imagined she'd also have to be 'the Internet police.' As head of Bozeman High School's library department, Coppersmith knows that an important part of her job is to help students learn to use the Internet wisely. Yet today's librarians also have to be vigilant to make sure kids aren't abusing Internet privileges on school computers -- by ... cruising for sexy sites.... It's only a few who violate the rules, and most are contrite when caught, she said. 'But a few are being extremely persistent.' .......