It's probably better for them not to be quiet. To get rid of them you need them to speak up and identify themselves.
https://en.wikipedia.org/wiki/Hundred_Flowers_Campaign
Mao did this in China. In 1956 he told everyone to be honest and encouraged them to criticize his regime. Then he spent the next two years putting them all in labor camps. To deal with the racist problem, Google, YouTube, Facebook, Reddit, etc should do the same thing. Instead of firing James Damore encourage him and get everyone who supports him in Google to speak up,
then fire Damore and all his supporters.
@previous (C)
Why am I weird? Because I don't like shirts that encourage people to censor themselves?