they can only meet with people who have expressed a desire for someone to come study with them or who choose to attend their group.
This is the same in the prisons in England. And the prison chaplains quite often make it difficult to even meet up then. Bible studies often take the same format as a legal visit, although its been 4 years since I know of this happening(I started the study myself). Prisons have very complicated rule covering every aspect of prison life, and unless you get to know them well you can find it very difficult to get anything done.
Gadget