When you are trying to sign up you can select a censored option:

>>Censored Internet access - restricted access to unpublished government mandated filter list - but still cannot guarantee kids don't access porn

As explained here: http://aaisp.net.uk/kb-broadband-realinternet.html

The option are:

- Unfiltered Internet access - no filtering of any content within the A&A network - you are responsible for any filtering in your own network, or

- Censored Internet access - restricted access to unpublished government mandated filter list (plus Daily Mail web site) - but still cannot guarantee kids don't access porn.