I was going to make some snarky comment about whether the "controversial" ideas here include the moral necessity of the proletariat revolution, the need to abolish and prosecute the police, a defense of open borders, etc. But in fact the articles in issue 1 (https://www.journalofcontroversialideas.org/volumes_issues/1... - click "Read more" -> "Full article" -> "View Full-text" on any of the articles to see them) include
- a defense of violent action to protect animals, as done by various animal-rights activists
- a rebuttal of a paper claiming that "women" are "adult human females" (by which I assume is meant "cis females"), which replies that the paper gives no reason to dispute that trans women are women
- a dive into the merits of blackface-ish traditions, which ends up concluding that the Dutch "Black Pete" character is not actually defensible (though others are)
- an argument in favor of "global enlightened despotism" to save the world from climate change
It isn't literally a call to guillotine every billionaire, but it's a whole lot closer than I expected it to be. Yes, there are also papers in here arguing that left-wing opponents of scientific racism are no better than young-earth creationists, that you shouldn't deplatform Steve Bannon, etc. But I came in expecting it to be only that and it isn't.
(I do agree with another commenter's point that, essentially, most of the ideas here - especially the counter-rebuttal by the original author of the "Are women adult human females" paper - are firmly within the Overton window of discourse, and so this journal is not strongly succeeding at widening the window.)