Via FourthAmendment.com, this report by John Fontana of ZDNet:
A woman who pleaded the Fifth Amendment before being ordered by a federal court to provide a password to decrypt a computer hard drive is appealing the order and now citing the Fourth Amendment.
The case drew national attention when the accused, Ramona Fricosu, argued that surrendering a password was a violation of her Fifth Amendment rights, which protect against self-incrimination.
Read more on ZDNet. However this turns out, this case is one that will be talked about for years to come.