Reset your secret tokens if you believe someone has unauthorised access.
Secret tokens are used to allow you to export news feeds and calendars (RSS and iCal) that normally require a username and password to other sites and devices. They are also used in mobile apps and the email gateway. You should always reset your secret tokens if you believe someone has gained access to any of the above.
Select your name, then choose Account Settings from the drop-down.
Any saved links to RSS or iCal feeds will have changed, so you will need to collect and subscribe to them again. The email addresses you use to submit work and upload files will also have changed. Lastly, if you are logged into any mobile apps you will also need to log out of them and log in again.