This can be done. If your Network has a WCCP Router that redirects the Traffic to the server which has the content,
you can configure an Access-list and thus allow or deny users or IP addresses. Here's the configuration required:
ip wccp 0 redirect-list 120
access-list 120 deny tcp host 10.10.10.10 any
access-list 120 permit ip any any
I am not sure about how to restrict the website