Valve has changed how the Steam Family Sharing works by adding two-factor authentication and lender approval process.
Valve wants to ensure more control in the hands of lenders thereby reducing the risk of VAC and other similar bans that may results from unknown and unauthorized users accessing a user’s shared library from unauthorized systems.
Under the new Family Sharing you will be able to grant access to your library to 10 accounts from up to 10 machines. “Family Sharing is now a two-factor authorization process, where up to ten Steam accounts on up to ten machines may be authorized to share your library at a given time”, explains Valve.
“Any of these ten users may log into any of your ten authorized machines to access and play your shared games.”
The Family Sharing option, which is currently in beta, was announced back in September 2012. The service allows users to share a library with their friends and family while tracking achievements and save data individually.