> In fact someone changed those tweets from “white males” to something else and got banned from Twitter.
The point is that "white males" are no group protected by any anti-discriminatory law or fall under any "group" that is discriminable against under moral terms. You can legally and ethically flame against "white males" as you choose.
The reason is simple: as a collective in Western societies, white males occupy most of society's leading roles and (together with white women) form the majority of Western countries' populations. Discrimination, however, requires a power and numbers majority of the discriminators over those "discriminated"... which simply isn't the case, no matter where in the Western sphere you look.
Granted, the demographich statistics for the US show that whites may sooner or later no longer be the dominant ones by numbers... but as long as the representation of non-whites, especially black/brown people of color or people of latino and Asian origin, in ALL OF society is not representative of their numbers, whites simply cannot be discriminated against.
As a reason, there's no problem when Twitter bans people who post such stuff.