Remember that guy in Shawshank Redemption who engineered an ingenious escape through the sewerage? Prisoners today have it so much easier: the ubiquity of cell phones makes it so much easier to plan exit strategies.
Not that prisoners are allowed to transport cell phones into the confines in the first place. It's just not that hard to get phones into their hands when needed. One of the common strategies is to launch phones into prison premises via a cannon like device. Such ease of access to phones also means credit card fraud and the use of cell phones as blunt weapons are on the rise in American prisons.
But a recent demonstration showed how it was possible to jam all cell phones within the jail area ensuring they could not be use for communication purposes. You would think that would solve the problem. But turns out that the regulations require that cell phone jamming remain in the domain of the federal government so state jails can't make their own decision. It will take some time for such a decision to be approved given all the red tape involved. Till then, jailbirds will be waiting to get their hands on another cell phone.