Social Engineering

Let's say you're sitting at your favorite coffee shop working on your laptop when a friendly but frustrated patron comes over to your table. He had a coupon for the cafe, he tells you, but it's in his email and he forgot his phone at home. Could he bring it up quickly on your computer to get the coupon code?

Being the kind, helpful person that you are, you readily agree. You are also cautious, however, and make sure that you can see the computer screen the whole time as the man brings up his email and opens a PDF for a quick look at its coupon code. He then thanks you and logs out of his email, allowing you to get back to work.

A good deed done? Or....