The reason is that law, the Electronic Communications Privacy Act, is old, and technology has far surpassed the vision of the lawmakers who wrote and passed it in 1986. Almost no one used e-mail then, the online cloud didn't really exist, and storing personal information for long periods of time with a third party such as Google didn't seem to make any sense.
So, the law says, if users keep e-mail on a third-party server for more than 180 days, they've abandoned the material and law enforcement can look at it, armed merely with a subpoena, not a warrant from a judge.
Now Americans store years' worth of e-mail online, compose everything from professional documents to love letters on cloud-based word processors and keep all sorts of other files on remote hard drives owned by communications companies and located far away from their homes.
It's not just metadata that's vulnerable here, it's the full contents of every stored e-mail and every cloud-based document. Journalists, among many others, use these tools, which is why the Newspaper Association of America, to which The Washington Post belongs, is part of the Digital Due Process Coalition, a group lobbying to change the law.
For years, Sen. Patrick J. Leahy, D-Vt., chairman of the Judiciary Committee, has been trying to do that. Though his updates would keep multiple exceptions for law enforcement, his reforms would at least require government investigators to obtain a search warrant when they want to obtain e-mail content of any vintage from third-party companies.
This would not only meet Americans' legitimate expectations of privacy, it would also moot the legally murky question of whether searches conducted under the old law are constitutional.
Unlike some of the tougher issues the country is confronting following the NSA leaks, this one is easy. Congress should finally act on Mr. Leahy's bill, and soon.