Sort of a minor point but I wonder though if the quote meant prison rather than jail. Anecdotally I've heard that it is hard to get drugs in jail, but very easy in prison. This makes sense because people in jail are there for short stints and thus don't have time to make the connections required for a clandestine black market. A lot of people use the terms jail and prison interchangably, though they are technically different in the USA.
