Edward Wyatt / New York Times News Service

In a move to protect the privacy of Americans as they use the Internet on their smart devices, the Federal Trade Commission on Friday said the mobile industry should include a do-not-track feature in software and apps.

An FTC staff report, released Friday and approved by the commission, wants the mobile industry to take more steps to safeguard personal information. The move is nonbinding but is an indication of how seriously the agency is focused on mobile privacy.

As if to emphasize that, the panel separately fined Path, a 2-year-old social networking app, $800,000 — charging the company with violating federal privacy protections for children by collecting personal information on underage users, including almost everyone in users’ address books.

The report lays out a clear picture of what sort of activities might bring a company under investigation — like, for example, conveying the impression that an app will gather geolocation data one time only, when in fact it does so repeatedly. “This says if you’re outside the recommended behavior, you’re at a higher risk of enforcement action,” said Mary Ellen Callahan, a partner at Jenner & Block and former chief privacy officer for the Department of Homeland Security.

For companies like Apple, Google, Microsoft and Amazon, the suggestions essentially carry the weight of policy.

But the FTC also has its sights on thousands of small businesses that create apps that smartphone users can download for a specific service. The introduction of the iPhone created a sort of gold rush among startups to create apps featuring games, music, maps and consumer services like shopping and social networking.

The commission has begun to focus on mobile data privacy partly because smartphones let so many entities gain access to personal information, including wireless service providers, mobile operating system developers, handset manufacturers, app companies, analytics outfits and advertisers — “a degree unprecedented in the desktop environment,” the report said.

Together the actions represent the government’s heightened scrutiny of mobile devices, which for many Americans have become the primary way of gaining access to the Internet, rather than through a laptop or desktop computer.

“We’ve been looking at privacy issues for decades,” said Jon Leibowitz, the FTC chairman. “But this is necessary because so much commerce is moving to mobile, and many of the rules and practices in the mobile space are sort of like the Wild West.”