1. A method comprising: receiving an image to be shared with other users based on input from a first user; identifying a second user from a tag of the image, the identifying comprising: comparing a hash value of an email address in the tag to hash values of one or more email addresses in an email address record of the first user; identifying an email address in the email address record that has a hash value that is the same as the hash value of the email address in the tag; and providing information, based at least in part on the tag, to the second user using the identified email address.