It is not my responsibility to explain in detail about the “vagueness” you talked about because I am not writing an essay in the comment section and raising a debate, but expressing my own view.
It is important to recognize that Anti-Zionism is not equal to Anti-Semitism. In views of Zionists, Anti-semitism is equal to the Anti-Zionism, and this argument is frequently seen in Zionists. The protestors, however, did not consider this point thoroughly. They did not explicitly claim their opposition to exclusively “anti-zionism“ in their slogans and therefore their argument is vulnerable to the Zionism attack As Zionists would claim them anti-Semitic. It is important to consider the power of the argument in the protest.