Yes, Wiccans are allowed to worship in prison. Unfortunately, many Wiccans are not afforded the opportunity to do so, and often those who are allowed to do so are simply not able to practice Wicca, because of the limitations of the prison system.
Wiccans are usually very limited as to what they are able to do. It is difficult to receive Wiccan books and publications, not to mention ritual tools, and while mainstream religions are well represented within prison, Wiccans are seldom able to obtain outside sponsors.
Often, prison chaplains, who have staff pulling them one way and inmates another, do not fully understand the Wiccan faith, and just are not sure of what to expect from Wiccan inmates, let alone how to enable the practice of the Wiccan faith within the prison chapel. CirclesBehindBars is trying to fill the void, by providing Wiccan inmates, their families, supporters and friends, along with prison chaplains, the resources that will allow those Wiccans and other Pagans who are incarcerated the ability to practice their faith.