Google has followed in the footsteps of Facebook by changing its Google Reader to make shared items automatically available to Google Talk contacts.

However, as users know, not all IM contacts are friends: many are acquaintances or people users barely know and with whom they may not want to share a reading list.

Google has been crucified in the blogosphere over its Google Reader change, with bloggers saying the Google Talk contact sharing feature should be opt-in, not opt-out.

To calm users, Google posted an item on the Google Reader Blog that explains the company's reasoning behind the change and tells how to clear the shared items list and how to tag items to share with a limited number of people.

"We'd hoped that making it easier to share with the people you chat with often would be useful and interesting, but we underestimated the number of users who were using the Share button to send stories to a limited number of people," the blog says.

Recently, Facebook was forced to modify its new Beacon ad targeting service that notifies users' friends in the network when they buy things on sites of Facebook partners. Facebook made that an opt-in feature, however, after consumer groups and Facebook members complained the service violated people's privacy.