I won’t say which ones, but BT have taken it upon themselves to prevent access to some web sites urls.
There is a way round this using a proxy service called Tor, I’ll show how for Xubuntu. Tor also offers benefits of more anonymised browsing on the interweb.
First off, add the Tor ppa to your sources, open a terminal and:
sudo nano /etc/apt/sources.list
deb http://deb.torproject.org/torproject.org precise main
to the bottom of the file (replace “precise” with your distribution version)
Staying at the command line add the gpg key:
gpg --keyserver keys.gnupg.net --recv 886DDD89
gpg –export A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 | sudo apt-key add –
sudo apt-get update
If error free you can then add tor:
sudo apt-get install tor
then install polipo
sudo apt-get install polipo
Make sure the services are started (from now on tor and polipo should run on boot):
sudo /etc/init.d/tor start
sudo /etc/init.d/polipo start
Check tor is running on port 9050
ss -aln | grep 9050
You should see something like this:
LISTEN 0 128 127.0.0.1:9050 *:*
I use Firefox, so now to add some settings to enable the proxy:
Edit > Preferences > Advanced > Network > Connection > Settings
Tick the Manual Proxy Configuration radio button
Add 127.0.0.1 to the SOCKS Host line and change the port to 9050, then OK.
Finally, because Tor can be a bit slow, you may only need it for sites BT is blocking, so fetch the Toggle Proxy add-on which will add a toggle button between manual and system to your add-on bar (or you can set keyboard shortcuts)
If all went well, you should now be able to browse more securely and freely using tor
You can also add your tor configuration as a relay to support the anonymised tor network, making things faster for you and others.