A sensitive species is defined by NatureServe and their international designation of sensitive species (http://en.wikipedia.org/wiki/NatureServe_conservation_status). eButterfly updates these as announcements from NatureServe become available. Also each user can choose the sensitivity of their data in the checklist process. The default is public, but you can choose to hide it from everyone but eButterfly administrators, or everyone. Any data not designated as public will not be included in maps, graphs or rankings.