Use the lock icon when you make a status update to override your Facebook privacy settings for that single post.

Each time you make a post or create a photo album, you can use the lock icon to select who can see that post.

When submitting information, look for the "lock" icon on the browser's status bar to be sure your information is secure during transmission.

In this case, the lock icon in the browser should show the identity of either the bank or the operator of the verification site.

Look for the lock icon, a URL that begins "https:" and never provide personal information if you don't trust the site.

Also, you should notice a small lock icon in the status bar at the bottom of your browser window.

Chrome puts a nice red X over the lock icon and strikes the "https" text.

Encryption is toggled using a lock icon and signing with a checkmark icon.

The lock icon is something I've seen a lot of questions and misunderstanding about.

The easiest way to think about that lock icon, no matter where you see it, is "Only I can access this."