1. Protect the identity of persons requesting information delivery via public social media
1.1. Librarians
2. Security
2.1. Have a distinctly separate identity to protect secure information from job or work environment
2.1.1. Military
2.1.2. Healthcare provider
2.1.3. Religious
2.1.4. Corporate R&D
3. Identity
3.1. Separation of work and personal life
3.2. Have a stage identity for specific dramatic purposes
3.3. Hoping for a new lease on life in a new community
3.4. Personal branding
3.4.1. Common name hard to disambiguate
3.4.2. Someone else with the same name, but you'd rather not be confused with them
3.5. Frequent attacks by online trolls/griefers drown out your ability to communicate
3.6. Best known through identity used in online game, forum, or virtual world
4. Privacy
4.1. AlAnon
4.2. Healthcare patient support groups
5. Safety
5.1. Worker in controversial profession
5.1.1. Sex workers
5.1.2. Abortion doctors
5.1.3. Medical marijuana store owners and suppliers
5.2. High profile in main identity
5.2.1. Entertainers (some)
5.2.2. District attorney
5.2.3. Politicians
5.3. Victims
5.3.1. Stalker victim seeks to avoid discovery by stalker
5.3.2. Bullying victim
5.3.3. Battered persons in online support group seek to avoid discovery by their attacker
5.4. FBI Witness protection program, and similar circumstances
6. Stigma
6.1. LGBT
6.1.1. Especially transgendered
6.1.2. Especially intersex
6.2. Stigmatized diagnosis
6.2.1. Mental illness
6.2.2. Specific conditions
6.2.2.1. Alzheimers
6.2.2.2. ADHD
6.2.2.3. Cancer
6.2.2.4. Herpes
6.2.2.5. HIV/AIDS
6.2.2.6. Leprosy
6.2.2.7. Multiple sclerosis
6.2.2.8. Tuberculosis
6.2.3. Disability
6.2.3.1. Learning disability
6.2.3.2. Cognitive disability
6.2.3.3. Physical disability
6.3. Relationship to stigmatized person
6.3.1. Suicide survivor
6.4. Appearance
6.4.1. Facial difference
6.4.2. Unusual height or lack of height
6.4.3. Missing limbs