In 1986, Congress passed the Stored Communications Act, firming up Fourth Amendment privacy protections for email and other electronic communications. Since then, the government has had to show probable cause and obtain a warrant in order to get access to email maintained on an Internet service provider's server if it is less than 180 days old. But federal prosecutors in Colorado think they have found a loophole: If email has been opened and read, they say, it no longer qualifies as "stored communications," which refers to "temporary" storage and backups, so no warrant is necessary.
In December 2009, federal authorities used this argument to demand that the email host Yahoo! disclose the contents of messages stored on its servers, saying they were "relevant and material to the government's investigation" in a secret criminal case. In a brief filed on Yahoo!'s behalf, Google, the Electronic Frontier Foundation, and several other interested parties called the government's reading of the law "strained," saying it "contradicts [the] plain language" of the statute. It may also be unconstitutional: Case law suggests that stored email should enjoy the same Fourth Amendment protections as private papers.