Software bugs, or lets call them "features", come in all shapes and sizes. Some are a slight annoyance in your day-to-day while others might hinder your productivity quite a bit. But when these "features" lead to privacy issues then we really need to pay attention.
Ryan Coleman from Canada has discovered a privacy issue in Gmail which Google seems to be aware of and has included the details in their FAQ:
Why am I receiving someone else's email? You aren't really. If you receive a message that is addressed to a variation of your email address, it might seem like you are getting someone else's mail, but we promise you aren't. Gmail doesn't recognise dots (.) as characters within usernames, so you can add and remove them, creating many email address variations. For example, messages sent to GoogleAmy@gmail.com and Google.Amy@gmail.com are delivered to the same inbox. For your protection, you can't log in to your account using a variation of your address - you'll need to enter the exact username you used to create your account. If you entered dots as part of your username when you signed up for Gmail, please enter them each time you log in to your account. If you believe that a message was accidentally sent to you, you may want to contact the sender to inform him or her of an incorrect address.
But the question that needs to be asked is why did Google's registration systems for Gmail allow users to register accounts with the period (.) in it, when Google knew that the mail would go to both?