I know a person who has taken ownership of a life ins policy without the original owners permission, is this legal? 
An owner can not be changed on a life insurance policy without the legitimate signature of the original or current owner . If forgery is involved it will not stand up in court if challenged . Just be sure you are not confusing the owner of the policy with the insured on the policy . It does not necessarily have to be the same person . For example , if the policy was written on a minor child , the parent would be an owner even years later if never changed . The only exception to an owner not signing over policy ownership is court ordered incompetence . Then someone with power of attorney could transfer ownership of the policy and it would stand in court . 