A Symphony Messaging chat room cannot be deleted by a user or an administrator for compliance reasons. It can only be deactivated (see how to deactivate a chat room) by the owner of the room and then locked by a Compliance Officer (CO) or Super Compliance Officer (SCO).
When a chat room is deactivated, users will no longer be able to view the content within the chat room or search for it, unless the original owner reactivates it (see how to reactivate a chat room).
In addition to deactivating a chat room, CO/SCOs can also lock a chat room (see how to lock a chat room).