Agents are increasingly searching smartphones at the border. This lawsuit wants to limit that.

The American Civil Liberties Union (ACLU) and Electronic Frontier Foundation (EFF) sued the federal government in hopes of curbing the wide-ranging ability of federal agents to search and seize the smartphones and computers of travelers — including US citizens — as they arrive on American soil but have not yet formally entered the country.

The practice, which remains rare but has grown more frequent in recent years, allows agents in border zones such as the arrivals areas of international airports to sidestep the Supreme Court’s landmark Riley decision in 2014 requiring that law enforcement officers get search warrants before examining the contents of digital devices.That ruling grew from the long-running contention by civil rights groups that modern digital devices carry such massive amounts of data and such sensitive records — including photographs, location data, e-mails, videos and Web browsing histories — that they should be afforded full Fourth Amendment protections against searches and seizures without warrants.

Sept 13's suit demands stricter legal standards for device searches in border areas. They argue that relatively lax rules established for searching luggage or goods bought in duty-free shops should not apply to modern smartphones, tablets and laptop computers routinely carried across borders. The suit says that the number of such searches — conducted by Customs and Border Protection agents, sometimes with the assistance of Immigration and Customs Enforcement — has grown sharply in recent years and is on track to hit about 30,000 in the current fiscal year. That remains a tiny fraction of the several hundred million travelers who enter the nation every year.