Google Reader added a useful feature for some of us who wants to have control over the shared items. It now allows you to select from Gmail contacts list who can see your shared items.
With the new controls you can allow all chat buddies to see your shared items, or you choose from your contact to those your shared items will be sent.
You can also manage who shares with you. When someone shares with you first time, you will get a notification, you can preview it and subscribe to their shared items. You can also choose to share your items with them or not.
Remember when your share items in Google Reader they are available with a Public URL, so even if you don’t share with some people they will still access your shared items if they know the URL.
Image Via Google Blog