Helping people die. They use confusion, a feeling of belonging if you are "in", and a feeling of superiority to make the weak minded who are "out" feel inferior.
There is a three segment show a reporter from London did about the CoS and the outcasts, and those who teach in other countries after being expelled. Using the same methods.
Ther is another one that was done in Germany (it is illegal there) where past members were beaten, and their lives damaged, and they have threats if they leave the country they will be killed. The reporter who covered the story was followed for weeks after by CoS "agents" as he called them. Alot of hie personal life was messed with, "anonymous" things faxed to his employer and family.