What is antisemitism is people shouting sieg heil outside my house when they read my name on the door thinking I am Jewish (I am not, though our family fled from German forces during WW2, not all survived).
Though I am not fully subscribed to the internet school of ”just ignore the trolls”, I think they should all be countered once or twice before being added to a blocklist. That way other people see that those trolls are not welcome and that voices are being raised against them.