Stack Exchange is now partnering with OpenAI. While the company has received a commitment from OpenAI that attribution will maintained, OpenAI clearly wants to do things (like training a transformer model) that aren't compatible with attribution.

I don't know quite what this partnership involves, but if Stack Exchange ends up liable for license violations then – after a period of 30 days, during which they could only "cure" the violation by making OpenAI destroy their latest model – Stack Exchange would no longer be authorised to use our contributions. So… in this hypothetical, what's the procedure for having our contributions removed from Stack Exchange?

The procedure is not:

• DMCA takedown notice. DMCA's OCILLA "safe harbor" provision doesn't apply if Stack Exchange is the knowing violator, so we don't need to "under penalty of perjury" anything.
• Mass deletion. The software doesn't let you delete well-received posts, and mass-deletion is currently considered vandalism.
• Blanking edits (except as an interim measure). This is also currently considered vandalism, though I suppose we could change the rules if it came to that.
• GDPR erasure request. Most of the time, contributions are not personal data: all this can achieve is waiving the attribution requirement for your contributions, pursuant to CC BY-SA 4.0 §3(a)(3), though it won't waive the ShareAlike provisions.