Facebook, one of the most visited and best social networks all around the world, is blocked at schools and offices as it just wastes time and is not useful. Just like many other sites like twitter, hi5, myspace, facebook too is blocked. But one always just tries to open it in one or the other way, to access the social networks.
One of the best and most essential ways, but also a risky one is the usage of Unblocked Proxy sites. The proxies are the 3rd party websites which create a new gateway for your computer so that the websites that are blocked in your normal IP, can open from the newly created IP channel. You need to keep checking whether the proxy site is unblocked or not, as the school security systems mostly keep updating with the list of new proxies that are blocked, so you should just keep a list of new proxies that are still not blocked.
But, proxies too are not very genuine and may pose a serious risk to the users as some proxies are made by hackers to just steal your Login credentials and hack your account. So you have to also check for how much genuine the proxy site is.
Also, apart from the security risks, the proxy websites are very slow and difficult to open as they have a big job to be done and there are many users who frequently keep using these proxies for browsing many websites, not just facebook. So you would always need to keep switching and searching for newer proxy sites.
There are a few apps on facebook that claim they can help in making you unblock facebook while at school or office. But most of them just don’t work, so proxies are the only option you are left with. Its not just facebook but many other sites like Xanga, Hi5, Friendster, MySpace, Orkut, Bebo, AIM Express, Rapidshare, Megaupload, MSN ( Live), Hotmail, GMail, AOL, Yahoo Mail etc. which are mostly blocked by offices, so that the person is focused at work.
One advice is to better stay safe and use the websites only when its available for access, because sharing your login credentials in unsecured facebook login pages would be risky.