Prisoners are using a new social networking site to post potentially sensitive information, protest their innocence and even look for love on the outside.

The world-first website, iexpress.org.au, has been established by prisoner advocacy group Justice Action to help inmates' rehabilitation by providing a platform for self-expression and aspiration.

Prisoners can ask Justice Action to upload any images and words to their profile and set up a personal email address for contact with the public.

Justice Action co-ordinator Brett Collins believes the publicly-accessible website is a "game-changer" that will "explode" with popularity.

Two dozen inmates have already set up profiles, including Sydney murderer John Meyn and "Little Pebble" cult rapist William Kamm.