Twisting Karma

I know that knocking is not good, but here I received a message from one of the users (and I don’t just believe me there), after which a dialogue of the following content took place.

A user wants to join the 1st circle of your friends.
> I propose to add each other as friends, so that you can raise each other's karma.

- I rejected the offer

> Will you increase my karma? I promoted you! I can minimize, in fact, I have good intentions! :)
')
Why blackmail?

> Oh, you! :) Stay with my fat plus! I do not mind!

Maybe I was wrong, but I lowered his karma.

> Why do I need to lower my karma?!?
> I wrote, leave you +, I do not mind!
> Now or you will raise me and I will leave my plus; or I'll lower you too (with my karma, this will be a significant minus !!!)

I am writing now here to hear your comments. My opinion is that this is simply not fair. The person can be seen in the general list