Contracts and ‘Reasonable Expectations of Privacy'

From Cato @ Liberty:

Chris Soghoian looks at a recent ruling related to the ongoing investigation of Wikileaks, in which a judge rejected a challenge from several users whose Twitter account information had been obtained by the government. Thanks to a shortsighted Supreme Court ruling from the 1970s, people are presumed to waive their 'reasonable expectation of privacy' in data voluntarily conveyed to third parties, which means many types of sensitive records can routinely be obtained by the government without the need for a full-blown Fourth Amendment search warrant based on probable cause. In some cases, a mere subpoena, or even a government agency's certification that the records are 'relevant' to an investigation, will suffice.