quite correct
from 'answering Islam' website
But more serious is the case of the Jews in Medina and other surrounding towns. In the year 7 of Mohammed’s regime, a campaign was carried on against the Jews in Khaibar. In Medina Mohammed dealt most severely with the Jews who opposed him. The Jews ridiculed his understanding of the Old Testament and to them it was obvious that he knew little of it, although he has a passage in the Qur’an that the Old Testament was to be read and honored.[2] The first episode was against a Jewish tribe by the name of Banu Kainuka. A Jew played a prank on a married Arab woman by fastening the skirt of her dress to her shoulder. The Jew was killed by a Muslim, and the murdering Muslim was then killed by the Jews. After that the Jews were locked in their quarters by Mohammed. They were forced to surrender all their possessions to him, and then were allowed to move to Syria.
The men of the tribe, Banu Karaiza, were not as fortunate. They had not supported Mohammed during the Meccan siege of Medina. The judgment against this tribe was that all the men of the tribe were to be put to death, and all the women and children were to be sold into slavery. There were over 600 men massacred in this vengeance. Andrae says about this slaying and its commentary on Mohammed’s personality, "One must see Mohammed’s cruelty toward the Jews against the background of the fact that their scorn and rejection was the greatest disappointment of his life, and for a time they threatened completely to destroy his prophetic authority."
This is actually widespread common knowledge and anyone denying it, spinning it or glossing over its historical significance for modern times, is at the very least incompetent in even the basics of the history of religion.