Honestly it’s probably a losing battle, but if you want to try then organisations like CNN and Wired have guides as to how to opt out of letting the big social networks strip-mine your personal data in order to sell it to any rich-enough enterprise interested in ‘improving’ their AI model.

Except Reddit, because apparently there’s no way to prevent that.

Of course this doesn’t help retrospectively. Many companies have already sold or ingested your output, usually without asking. Making the changes outlined in the guides above won’t undo that.