People needed convincing that changing over to the new technology was worth the effort involved. We have had to deal with several issues. We did get teething problems. At first it took a long time to log on, but we sorted this sort of thing out within a few weeks. Parents get a copy of this and sign a consent letter.
Students then get an Internet users' card, which is withdrawn if they break the agreement.
We haven't had any problems with students getting hold of hard core pornography or other damaging material. In the most serious incident some boys downloaded inappropriate images and started manipulating them in photo-shop. We use auditor software, which allows us to monitor which sites each user visits. I simply confronted the boys involved with the log of their visits, took away their Internet User cards so they were effectively excluded from using the Internet, and denied all students access to the Internet for a limited time. We have had no trouble since.