Cemeteries in Munich allow QR codes as memorials on headstones, Mr. Hoerauf said, and for more than a decade, people whose loved ones are buried in cemeteries around the world have uploaded photographs and other digital keepsakes to create online memorials that can be viewed via QR code.

German police are investigating after over 1,000 QR-code stickers were slapped onto graves across three cemeteries in Munich. The small stickers, when scanned with a mobile phone, show the deceased person’s name and their location in the cemeteries.