An article on Blend Games contains a video they say demonstrates that item duping was possible in Diablo III before a hotfix addressed this. All the clip demonstrated for me is my inability to understand foreign languages, but this post explains how this took advantage of the game's checkpoint system to craft items at the cost of no resources, hopefully a moot point now that its fixed. They use this incident to once again question the game's inconvenient always-on DRM. They also discuss how Blizzard is handling account rollbacks in cases where accounts are compromised, taking issue with Battle.net account security as the launch of the real-money auction house for the action/RPG sequel nears. Speaking of which, this post (thanks nin via Kotaku) notes that Blizzard has changed the terms of service for Diablo III to require the use of their authenticator for real-money transactions:

Starting today, in order to add to your Battle.net Balance, players will be required to have a Battle.net Authenticator or Battle.net Mobile Authenticator attached to their Battle.net account. For clarity, this means you’ll need to have an Authenticator to add to your balance via Battle.net Account Management or to send the proceeds of your real-money auction house sales to your Battle.net Balance.

Please note that players who previously added Battle.net Balance to their account prior to this change will be able to use it to make eligible purchases on Battle.net and in the auction house without attaching an Authenticator. However, an Authenticator will be required to add to your balance in the future, as explained above.

While we understand that this creates an extra step for players during the login process, we believe this added layer of account protection will help foster a safer auction house environment for all of our players.

You can learn more about the Battle.net Authenticator, Battle.net Mobile Authenticator, and other account security information by clicking here.