The illustrative embodiments described herein provide a computer-implemented method, apparatus, and computer program product for preventing a set of users from accessing a message in an instant messaging system. The process determines whether a message received by a receiving computing device from a sending computing device is undetected by a set of users associated with the receiving computing device. The process notifies the sending computing device that the message is undetected by the set of users in response to determining that the message is undetected by the set of users associated with the receiving computing device. The process prevents the set of users from accessing the message in response to receiving a request to prevent the set of users from accessing the message.