I am seeing someone else's data

There are two possible explanations why you are seeing someone else's data:

• Are you using a shared computer, e.g. in an internet cafe?
  
  If the previous user fails to log out of their account when finishing up, their data is exposed to subsequent users of the machine.
   
• Are you receiving the email of someone else with a similar name in your Gmail?
  
  This is a commonly reported issue. Please see this article for a detailed explanation.