It has been proven pretty thoroughly that, when antisemitic speech is given a platform, the eventual result WILL be people going forward to take action in favor of antisemiticism. When this kind of hateful speech is not given a platform and not tolerated, and those that may potentially take action to harm innocent people are kept track of, needless violence is avoided altogether.
This us exactly why people say America isn't working. You have groups of people saying "well, this group allegedly kept records of people with different beliefs and decided to remove them. I think that what these period did is wrong, so we should find out how they are, and remove them.".