Dear Allanthung,
Yes an adminstrator who control Internet/Network filtering can block some or all websites. This is called Internet Filtering, and it includes deploying various internet filtering softwares/tools like Fortinet or widely used Websense, where he can create several categories to filter internet traffic like: shooping, public email, hacking sites, pornography, search engines, network proxies etc... You can try n use any online proxy site to access any blocked site. u will get a list of sites by Goggling "online proxy sites". It may possible that these sites will also got blocked....depends how good filtering mechanism has been configured.
Your second questions seems bit confusing "Administrator Strenght and his Capabilities Controlling the Client" what type of control you are asking about??? It is internet based control, system based control, access based control, policy based control??? Also you need to mentioned your network deployment whether it is Peer2Peer n/w or it is Domain based n/w???? If it is a domain based one, means you have to select domain while logging in along with username & password, then yes he (administrator) can have full control over your system using various domain policies & domain tools. Please reply if having any query.
Thanks,
Neeraj
