Where is that coming from ? That's a very lawyery way to phrase things.
"potential ?" where I live I think people may max out their holidays and overtime (if lucky enough) and leave-without-pay but there would be a conversation with your employer to justify it and how to handle the workload.
In the USA, from what I read, it's more than likely that you would just be fired on the spot, right ?
edit: just googled a bit, where I live you must tell your employer why you will be absent if you go to jail but that can't be used to justify the breaking of the contract unless the reason for the incarceration is damaging to the company and... yeah, I am definitely not a lawyer :]