William Fitzgerald

sort of. Like on twitter, you can delete your tweets, but unlike twitter, the uhh "retweets(?) of your code ("Forks")" would still be around. A lot of people start off licensing very permissively, so retroactively pulling it doesn't necessarily restrict anyone.

A lot of people use the MIT or a creative commons license that give anyone an ability to do whatever. @creativecommons has a lot of variations https://creativecommons.org/choose/  GPL and other "copy left" licenses restrict corporate use, but distribution mechanisms (the internet)...

means that companies are often the end users, so they aren't "selling" the software, so they can still benefit from it being out there. And then there's "public domain," which I guess is more broadly applied than software, but kind of similar in effect (for me) to MIT license.

And then there's licenses that charge money, and this can be the case even if the "source code" (the means to reconstruct the software's effect) is available. There are lots of views and some laws, but these are the basics as I interact with them.

All this is to say that it's hard to move in an effective way, from a permissive license to something with restrictions (because adding restrictions retroactively would be a weird unstable clause if it was in the first license).

One additional thing, and relevant here, is that this code exists in places (repos/package managers/registries), and if someone can at least temporarily pull their code there, then it can break other people's code until a backup is found and links are restored to code copies.

Oh wait, unless you're asking the normative question of "could you, if you don't mind unpublish your code and break whatever palantir uses?" and that seems like a fantastic idea and a thing we should all do if we can.