Who determines when something is "antisemitism"?

And how are they determining that someone is being "antisemetic"? A talk on my disliking the censoring of those I particularly do not have anything against so long as they can reciprocate my actions in total. I do not go against anyone. When I am disrespected I am entitled to disclose the unprosecuted discord. Strong adult language and even some passionate yelling. Due discretion advised.