SAN FRANCISCO – Instagram, the popular mobile photo-sharing service now owned by Facebook, is the target of a storm of outrage, much of it on social media, after changes in its user agreement give it broader rights to use its members' photos in advertisements.

In a blog post that offered few details, Instagram said the changes will help its service "function more easily as part of Facebook by being able to share info between the two groups." Facebook Inc. also recently updated its privacy policy to allow for more integration with Instagram.

"This means we can do things like fight spam more effectively, detect system and reliability problems more quickly, and build better features for everyone by understanding how Instagram is used," the blog post said, adding that the updates also "help protect you, and prevent spam and abuse as we grow."