How romantic is the concept of a "Message in a Bottle?"
How about if there was some kind of digital service like this.
People can put their Messages (text, photos, videos) in a "bottle" and send it out to the world. On the other side, people receive the messages and can decide to either (A) keep the message or (B) throw it back. If a message gets discarded more than x times it would be transferred into a "unwanted" messages area.
Once you decide to keep that message, it's yours, nobody else can receive/see it. You can find out more about the person who sent out the "bottle" and decide if you want to send back a message (or not).