by Rob Pegoraro

Before concluding that “no reasonable prosecutor” would file criminal charges against Hillary Clinton for using a private email system as secretary of state, FBI Director James Comey called her communications habits–which on rare occasions included sending classified information via this unofficial channel—“extremely careless.”

Comey scolded the email practice of Clinton and her colleagues, criticizing the State Department’s entire security culture as “generally lacking in the kind of care for classified information found elsewhere in the government.”

But his harshest critique may have come towards the end of the remarks he delivered Tuesday morning, when the FBI director mentioned Clinton’s international email use.

“She also used her personal email extensively while outside the United States, including sending and receiving work-related emails in the territory of sophisticated adversaries,” Comey said. “It is possible that hostile actors gained access to Secretary Clinton’s personal email account.”

Tech-travel advice for the paranoid

Security experts agree: When you visit countries with a habit of snooping on their citizens and visiting Americans, you can’t use your devices and your apps as you would at home.

“I use the most secure devices I can, only bring the most absolutely necessary data and access with me, and wipe everything when I’m done,” said Rich Mogull, CEO of Securosis, when I asked him for advice before a business trip to China I made in April.

For one recent international trip, that amounted to taking only an iPad and iPhone. He wiped each device clean before traveling, then set them up with a subset of his usual apps that included virtual private networking (VPN) software to create a secure connection to U.S. sites.

He also used a prepaid SIM card for the iPhone instead of his regular SIM, which could otherwise be reprogrammed over the air.

Chris Soghoian, chief technologist with the American Civil Liberties Union, said he takes a Chromebook—he called it “a great, secure burner” device—for international travel. He endorsed a useful Chrome OS feature if you fear an inspection of your device by U.S. customs and immigration officials: “an easy-to-use ‘reset to factory defaults’ button in the settings.”

In certain destinations, it may be safer not to use your devices. That’s the plan Greg Nojeim, senior counsel at the Center for Democracy & Technology, settled on before a trip to Russia in May followed by more overseas travel—he’d keep his iPad off while in the country.

Fortunately, not everybody will be of interest to another country’s spooks. “If you aren’t a target like a corporate exec, government official, or security consultant/analyst, then you don’t need to worry as much,” Mogull told me.