AITA for using someones first name extensively in a venting post on r/venting? Just first name, no age, last name, middle names, locations, appearance or any other personal information.

After I vented I told them and they told me to take it down after saying "You have posted my name and slated me for the whole internet to see". So I took it down after I told him that there were no specifics to his identity at all. He also added that he could slate me back. 