There are a lot of possibilities to block access to specific internet pages. But before doing so, there are a couple of things to consider:
1. It's not possible to block everything that is deemed "inappopriate". There are always ways around the block!
2. Do you judge material that users bring with them, such as books and magazines? So why would you inspect their web trafic?
3. There are numerous ways around products which do impelement the site-block. E.g. webpages can be fetched via email. Users could use proxies. Hostnames can be entered as IP addresses, etc.
