I'd just like to point out, while the handwringing is going on over some random racist attacking an East Indian member of Baen's Bar over his chosen nickname, that the "Worldcon" has endorsed terrorism for literally decades.
I grew up in the UK, watching bombs blow up in the news. And the first time I attended "Worldcon," there's three assholes walking around in T-shirts for the IRA. You know, the murderous, torturous, bomb-throwing fucks who killed somewhere between 500 and 600 civilians in the UK and Ireland, and justified it as "Well, we don't like it, but it's inevitable." (Close paraphrase.) The organization that was declared terrorist in both the UK and in the Republic of Ireland, but conveniently chose "not to recognize their authority." When you literally refuse to recognize the people you claim to be fighting for, you may have a problem.
It's pretty disturbing for a young man who's seen bombs on the news, and been cautioned not to open packages because the terrorists sometimes get the address wrong, and trained never to move more than a few feet from your luggage when traveling in case it be deemed a threat, to watch terrorist sympathizers parading about singing songs about how glorious terrorism is.
And they were at every other fucking "Worldcon" I attended, too.
The only conclusion to draw is that WSFS endorsed that terrorist organization. When you let people mince about wearing shirts endorsing a publicly known, international terrorist organization, and make zero effort to stop them, you de facto endorse them.
That, btw, plus the increasing racism, anti-semitism (demonstrated yet again), and general white privilege of calling themselves the "World" science fiction convention (I've noted elsewhere, my readers in Bangladesh, India, Pakistan, cannot afford American or European prices to attend, and WSFS has made zero effort to choose marginalized nations for hosting) is why I haven't attended since 2003, and probably never will again.
No decent person should. Unless, of course, they're perfectly okay with terrorism, racism, anti-semitism, and other extremism.