The Wall Street Journal reports on the use of “infidelity phones” in Japan. Fujitsu’s older “F series” cellphones include privacy features that some people seek out, such as hiding missed calls or text messages:
TOKYO—Over the past few years, as many people rushed to trade in their old phones for smartphones, Japan’s philanderers have remained faithful to one particular brand: Fujitsu Ltd.’s older “F-Series” phones, which feature some attractive stealth privacy features.
The aging flip-phone—nicknamed the “uwaki keitai” or “infidelity phone”—owes its enduring popularity to customers who don’t believe newer smartphones are as discreet at hiding their illicit romances. […]
Fujitsu’s “privacy mode” is a layer of nearly invisible security that hides missed calls, emails and text messages from contacts designated as private. If one of those acquaintances gets in touch, the only signal of that communication is a subtle change in the color or shape of how the battery sign or antenna bars are displayed. If ignored, the call doesn’t appear in the phone log.
The changes are so subtle that it would be impossible to spot for an untrained eye. When the privacy mode is turned off through a secret combination of keys, the concealed calls and messages appear, and voice mail becomes accessible. […]
Fujitsu started offering the privacy mode in 2002 as part of more stringent security requirements for all phones offered by NTT DoCoMo Inc., Japan’s largest carrier. Takeshi Natsuno, a senior DoCoMo executive at the time, said he insisted on tougher security after hearing too many stories of couples splitting or workers landing in hot water because they left their phones out and unguarded. […]
These days, the devotion of infidelity phone users is being tested. Both Japanese carriers and Fujitsu are starting to phase out the older phones for an all-smartphone lineup. And a growing number of so-called cheater apps are looking to bring similar functions to smartphones.
As a result, Fujitsu has added some of the privacy features to its smartphone lineup. The company’s new models conceal calls and emails from contacts marked private. Like its older cousin, it alerts the users with a subtle change in the battery or antenna mark. However, the privacy mode requires a separate mail and address book app designed by Fujitsu, rather than the default email program and address book provided by the carrier.