Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium, including a method for providing content. The method includes anonymously linking at least two different identifiers associated with two different requesting sources. The linking uses an identifier that does not include any personally identifiable information. A request is received from a user to create a bookmark for a resource that was presented on a first device having an associated first identifier. The bookmark or a reference to the bookmark is stored. Bookmarks associated with the user are synched across multiple requesting sources using the anonymous linking. After synching, a request to access saved bookmarks is received from a user when accessing a second different device. Based at least in part on the synched bookmarks, the bookmark is provided, or a link to the bookmark is provided, enabling presentation of a resource associated with the bookmark.