

While these changes could improve Google's face recognition software and allow Google to add new social features, transforming Picasa Web's private tagging into Facebook's photo tagging is a radical shift. You're not the only one who can add tags to your photos: anyone in your extended network at Google+ (friends and friends of friends) can add tags. Name tags change their visibility too: if you have access to an album, you can see all the name tags from that album. You can view or remove tags at any time on the photos homepage in Google+ as well as the Photos tab on your Google profile," informs Google. By default, name tags by people in your circles are automatically approved. "You'll receive an email letting you know you've been tagged in a photo. He will get access to your photo and to the entire album that includes the photo. Adding a name tag to a photo is no longer a private action: your contact will get a notification that you tagged him. When you join Google+, all of this changes. By the default, the name tags from your public albums were hidden, but you could also hide the name tags from unlisted albums. The integration between Picasa Web and Google Contacts made it easy to associate your photos with some of your contacts. Picasa Web's face recognition feature helped you organize your photos. Some of these rules make Google's photo sharing service unusable for many existing users and it's important to know them in advance.

Even though it's not obvious, after you enable Google+ in your Google account, Picasa Web turns into a completely new app with a different set of rules.
