Compromising 2.0 or Deferred Retribution service

In many detective novels and films (and sometimes, unfortunately, in ordinary life), a person who wants to play safe, in an unpleasant situation, says words like “If you kill me and I don’t get in touch with friends in four hours, then they’ll compromise you trusted materials will be handed over to the prosecutor’s office. ” Or: “In the event of my disappearance, a bank cell will be opened in a week, where a suitcase of dirt is stored on you.” Etc.
But what if you make an online service where people can write a message, enter the addresses of the recipients, and set the date of the mailing? :)
For example, if a person doesn’t enter only a known code on the site in a week, then a message will be sent to the addresses of proxies. Which, for example, could contain passwords to the email addresses of the disappeared user, webmoney keys, passwords, or other information.
Additional features: just so as not to transfer valuable information into the hands of the service owners, you can create a password-protected file with some information and send it in advance to your friends. And through the service send only the password for this file.
You can also send out messages to people in two stages: for example, after a week of inactivity to one people, and after a month of inactivity to other people. Well, you can continue to think about various other features, protection against spammers, security, etc.
ps The term "delayed retribution" is taken from the book of S. Lukyanenko, "Atomic Dream."