The Roman emperor Titus ran havoc in Jerusalem in the First Jewish-Roman War, when not only resident Jews but also a lot of pilgrims from Egypt and Babylon were trapped in a chaotic siege (Flavius Josephus). Even to this day, this day is mourned by Jews.
To commemorate the Emperor Titus's victories - most notably the Siege of Jerusalem, the Arch of Titus was constructed by his brother.
How come this standing monument to such a brutal massacre is not declared "Anti-Semitic"?
(Yes, I know it has been used for other memories too - but still the major one is of Jerusalem's beseiging, and it's still named after Titus.)