LiveJournal provides an option intended to reduce the chances of search engines indexing a journal; however, the only way to make it completely impossible for such indexing to occur is setting the entry security to "friends only" or higher when first posting the entry. If an entry is first posted publicly, and then edited to reflect a higher security level, it may have already been indexed by a search engine in the time between the security edit. The popular "friends only" security option, which has since been adopted by Xanga and MySpace, hides a post from the general public so that only those on the user's friends list can read it. Some users keep all their posts friends-only. LiveJournal also allows users to create custom user groups within their group of friends to further restrict who can read any particular post, and to allow easy reading of subsets of a user's friends list.