Why would i need it?
If you will get a scam phone call, and person will say his name / surname, you can add him to the service so people will know his true nature.
Some person did something bad to you, you can rate him on this service so everyone will know that he can do that to them also.
Your best friend is the sweeties person you ever met? Rate him so people will know that they can trust him.
You know a person who harms animals? Rate him so everyone will know what type of person he is.
You bought some product on online store, and the person sent you a brick instead of a gaming laptop? Rate him so people will know.