A Japanese blogger who goes by the name Bakanabe and writes anonymously about picking up women, said he looked into buying a new device but found the privacy settings fell short of his current phone. Instead, he opted to refurbish his battered, three-year-old Fujitsu flip-phone with a new casing and a new battery.

“Women may want to check my phone for strange emails or calls when I’m not around. With Fujitsu’s ‘privacy mode,’ they can’t see that information at all,” he said in an email. “The key is to give off the impression that you’re not locking your phone at all.”

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.