Somewhat related, one guy began a startup that simplifies, through his website, the process for family members to shop and send stuff to inmates. All the products are within the prison's accepted stuff guidelines, as it seems this is a major PITA for people outside to figure out. He even made a deal with a major record label to start making hip-hop albums on cassette again.
Here's the link:
PS. There's was a discussion about this on HN some time ago. Couldn't find it on search.