Ronald Guilmette, a private security researcher in California who prompted me to look up this information, said printing things to an Internet-based printer set up this way might have made the printer data vulnerable to eavesdropping.

“Whoever set up their home network like that was a security idiot, and it’s a dumb thing to do,” Guilmette said. “Not just because any idiot on the Internet can just waste all your toner. Some of these printers have simple vulnerabilities that leave them easy to be hacked into.”

More importantly, any emails or other documents that the Clintons decided to print would be sent out over the Internet — however briefly — before going back to the printer. And that data may have been sniffable by other customers of the same ISP, Guilmette said.