How to Sign Out of Yahoo on an iPhone
Accessing your Yahoo! Web page on an iPhone is a quick and painless task. You only have to sign in once to Yahoo! and you won't prompted to log in again until you you've ended your session and logged off. While this can be very convenient, it also allows anyone who picks up your iPhone while it is not passcode-protected to open your Yahoo! Web page and view your account settings and other personal information. Prevent this security lapse by signing out of your Yahoo! account when you are finished accessing the website.
Log in to your Yahoo! account on your iPhone if you have not already done so and Navigate to your Yahoo! Web page. Browse until you are ready to leave the Yahoo! website.
Touch your finger to the iPhone screen and move your finger up to scroll down the screen. Repeat this process until you reach the bottom of your Yahoo! Web page and the page will not scroll down any further.
Tap the "Sign Out" link, which appears just above the Yahoo! copyright notice. You are logged out of your Yahoo! account and the Web page automatically refreshes.