THE last time the Electronic Communications Privacy Act (ECPA) was significantly revised, brick-sized cellphones cost $3,000, email was mostly limited to academics and the military. The World Wide Web was still just a gleam in the eye of Tim Berners-Lee.

The law, passed in 1986, set forward-looking standards for government monitoring of cellphone calls and emails. But advances in technology have rendered the act as obsolete as a floppy disk. Federal law enforcement’s willingness to exploit outdated privacy protections mandates an immediate upgrade.

ECPA requires law enforcement to obtain a warrant — requiring probable cause and review by a judge — for records fewer than 180 days old, the outside window for data retention in 1986.

After 180 days, the standard has been interpreted as dropping to a simple law-enforcement subpoena, allowing records to be seized without a judge’s approval — or your knowledge. A technology unforeseen in 1986 — cheap electronic storage on cloud servers — now renders those provisions absurd, and creepy.

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U.S. Justice Department memos, obtained this month by the American Civil Liberties Union, show why. The federal government says it can obtain geolocation data via your cellphone — allowing your movements to be tracked — and obtain stored electronic records — emails, tweets, Facebook chats, etc. — without a warrant.

This creates an irrational disconnect between Fourth Amendment protections for hard-copy records versus those stored on the cloud. Print out an email, and police likely need to get a warrant to get it. Store it on the cloud, and no warrant is needed.

Updates to ECPA are pending in Congress, and are supported by a host of digital companies, including Microsoft, as well as liberal and conservative groups. In the House, former Microsoft executive Suzan DelBene, D-Medina, co-sponsored HR 983, giving Washington a savvy advocate for reform. Attorney General Eric Holder, under questioning from DelBene this week, acknowledged that an update was needed.

Narrow exemptions for foreign intelligence surveillance and law-enforcement emergencies — such as allowing police to track the geolocation of a suspect in a manhunt — should remain.

But the government’s creepy, warrantless reach into our digital lives should soon be as outdated as a dial-up modem.