How do I stop people reading my iMessages as they come in?
Solution 1:
If you mean from the Lock Screen or Notifications Centre, then
Settings > Notifications > Messages
switch off Lock Screen &/or Notification Centre
.. or if you simply want the content of the messages disabled, lower down the screen [out of sight on this image] uncheck Show Previews - though that will show who sent a message, but not the content.
