Step 5: What’s Happening on Your Device (over a “censored” connection)

Many computers in schools, libraries and Internet cafes (and even some in homes and businesses) contain software that directly prohibits requests for certain content. This sort of filtering is often associated with shared, publicly accessible devices or personal devices that are administered by someone in a position of authority (such as a parent or a corporate IT department).

At Public or Private Internet Access Points
There could be locally installed internet filtering software at your workplace, library,Internet cafe, etc. Technically, such software could be installed on any of the routers between you and the server you are trying to access, but we typically associate access point filtering with businesses, shared computers and publicly accessible (freely available or for-fee) Internet connections.

At ISP and Country Level
Your ISP, which naturally has the ability to see any direct requests you make Online, can implement filtering either by preventing your request from reaching its destination, or (less frequently) by preventing the response from reaching you.
•Some countries take a more hands-on approach, requiring that certain types of Internet traffic be routed through servers that are under the direct control of a particular government agency.
•This technique is sometimes applied specifically to requests for international content, as governments often take a more direct approach to the censorship of material that is hosted on servers located within their borders.
Many national filtering policies are implemented at the ISP level – in fact, many ISPs are government-owned and operated.
On the Server You’re Attempting to online services are sometimes “defaced,” in order to prevent them from responding to requests for content, regardless of where those requests might be coming from.
•The most frequently used form of such ‘defacing’ is when a site is overloaded by denial of service (DoS) attacks, that weigh down a site’s servers with ‘fake’ requests to the point that it cannot serve content to ‘real’ user requests.
•Such attacks can be carried out by anyone with access to the right software and a large enough network of computers (or who can afford to “rent” the necessary resources).
Finally, while we don’t usually think of it as a “blocking” or “filtering,” a service can prevent you from accessing its own content based on any number of things: your IP address, the country from which your request was sent, the preferred language specified by your browser, etc.