Here's a hypothetical situation for you:
What would you do if you saw the email below, with the subject line, "Apple ID: Your Apple ID has been disabled for security reasons"?
At first glance, the design elements of the message make it look like it could have legitimately come from Apple. The message says that your Apple account has been suspended, and that you need to click on a link (which looks like it will take you to Apple's website) and update your billing information to prevent your account from being deleted.
Would you click the link?
Hopefully, your answer is an emphatic "No!" Even though this email appears legitimate, it isn't. It's a phishing scheme designed to trick you into giving away your credit card information. How can we tell, you ask? Well, there are several telltale signs of a phishing scheme here, but the most important one is this: the request for updated billing information makes no sense. If your Apple ID had been compromised, you would need to change your password, not update your billing information.
Really, you should be wary of any email that asks you to click a link to provide sensitive information, expecially information that links directly to your finances. Some companies may send legitimate emails asking you to update this kind of information, but you can always go to a company's website, log into your account, and update it that way instead of clicking on links that may be suspect. For that matter, you could call the company directly as well.
Anyway, the moral of the story is: be extremely careful about clicking links in emails that ask you to provide sensitive information. Feel free to contact us if you think you've come across a phishing scheme or think you may have fallen for one.