The actual way to do this is how engineering guilds do it. “We cannot in good faith sign off on this building, we do not believe it’s safe.”

They’ve been highly ethical over a long time. As a result anyone who wants shifty engineering work has to go to dark places.

A software engineers’ guild could do the same. It could publish a code of ethics, which members then act collectively in accordance with. Guild labor - the best educated folks who have indemnity insurance etc. - won’t be able to be used to build things outside the code. For example if the whole guild refused to build engagement-jacking machinery like personalized feeds, it’d drive up the cost (and risk!) of getting them built, & impact the business case.

It only works if things are done transparently; if the code of ethics is too fringe or it changes too much, or people self-sabotage by attempting sabotage, the guild will fail to acquire market power and fail.