Nathan Newman, who works for Joshua Michael Marshall's Talking Points Memo, was on Amtrak researching racism and attitudes towards elites, and he first found that he couldn't access a racist site called Stormfront, even though he's an anti-racist doing research. That's because Amtrak, for inscrutable corporate reasons, uses Barracuda Web Filter.
And then, searching for a way around the stupid filter, he managed to find my own article, Internet Filters—Private Sector First Amendment Workaround, or Gov't Censorship In Disguise?, and couldn't access VDARE.COM, either.
Our experience is that these corporate filterware providers usually back down when threatened. But we depend on readers reporting instances to us. Many thanks to all of you who have.