Can you give an example?

Generally speaking, it seems to be clear that accusations of "antisemitism" have become a way to shutdown discussion and make someone you don't like an untouchable. It is a form of ad hominem. (A small historical note: the term "antisemitism" comes from the 19th century and refers to a racial prejudice against Jews, whereas the traditional antipathy toward Jews qua Jews was largely theological, moral, and social in nature, but certainly not racial which is a later development.)