I am not so sure. The General Data Protection Regulation (GDPR) includes a provision that ¡°The data subject shall have the right to withdraw his or her consent at any time.¡± I¡¯m not sure how that would apply, but I gather that it is intended to protect people have granted permanent rights to certain data and later regret it.
Not applicable in the slightest. Users explicitly grant rights to their content. I do understand wanting to remove one¡¯s posts. But if a group announces on the home page that removing is disallowed - just as, actually, the TOU makes it clear that users grant permanent rights - it seems fair enough.?