Both really. Aaron Swartz was not so conservative but Steve Huffman struck me as a libertarian bro long ago, and so absent Swartz the site began down a horrendous path that ramped up with the banning of leftist spaces like /r/chapotraphouse.
Also relevant on Steve Huffman:
The [Anti-Defamation League] said on Monday it's opened the Center for Technology and Society, complete with an advisory board stacked with notable names like Reddit CEO Steve Huffman, Facebook Vice President of Product Guy Rosen, and Bumble CEO Whitney Wolfe.
with the intent to obstruct a criminal investigation or immigration operation.
Intent is often one of the hardest things to prove in court cases anyway, often requiring additional sources of information to assess state of mind (mens rhea). At least, in a society where law matters. That said, if we assume US law matters at all (which you should never assume considering its historical actions), the stated goal of the site is for future prosecutions, as you've said and I agree.
Indeed it is, but fear not, for it's only because they're very bad powerful people defending a very bad evil society. Oh, perhaps some fear is warranted then...
Oh my, is that Senator Elissa Slotkin, "former" CIA Agent, from this famously disastrous interview? Well I'm sure a "former" CIA Agent would know a thing or two about compiling dossiers on American Citizens.
So there actually is a federal (felony) law against that, but not against sharing their names: 18 U.S. Code § 119. This is the most a website could legally get away with, at least for US Citizens. It may not apply to Ice List's designer (Edit: Who is Irish and living in the Netherlands, which I believe is part of 14 Eyes), but I am not a lawyer.