How to blackmail someone?

i guess you start with
Full name
age
Address
City
State/Country
e-mail
Family members
friends/family members e-mail
height, weight, eye color, hair color
hobbies
school/collage/workplace
phone number
facebook/twitter/myspace/google/youtube/skype account
passwords for above

Depends on the slave.
Not necessary private info. A face photo and a nude should suffice. Post those online while the slave would do anything to have them removed.

This way you dont affect his or her real life.

Just make sure the other person wants to be blackmailed. I have been blackmailed in the past and i hated it. Its not fun when its not consentual

Consensual means your limits and your safeword or safe exit.
You both agree in a blackmail fantasy play.

Mmmm it makes me so hard to imagine it happening to myself