You could call it returning to the scene of the crime. Anthony Weiner has rejoined the secret messaging app Confide, on which he had a months-long online sexting relationship with a 15-year-old girl. Users of the app — which allows people to communicate with messages encrypted for privacy that disappear right after they’re read and leave no digital trace — were shocked to see Carlos Danger is back in town. It seems that if Weiner’s personal e-mail was already saved in a user’s contacts, said Confide user got a message last week: “New friend. Anthony Weiner joined Confide. Send Anthony...