The previously mentioned problem of “right hand, left hand,” where people at an event have different informational norms, can create conflicts. For example, “John” may not want “Mike” to know that he is having dinner with Mike’s rival “Chris.” But Mike may learn this anyway if Chris tweets or blogs about his dinner with John. John can ask Chris to keep the dinner secret, but ultimately he cannot control how private this information will be.

Alice E. Marwick, Status Update, loc. 637