In Kemble Work, deleting a list item or a canvas comment that holds other people’s comments needs a workspace owner or admin who may delete anyone’s messages and outranks each author, and it is written to the audit log. In Kemble Circle, whoever started a private thread can remove members at their own level or below, and a ban’s clean-up leaves the replies of people at or above the moderator alone.
A poll is deleted with its message: its question, answers and who chose what, unless a legal hold keeps them, as the privacy policy now says. Where a channel withholds its earlier history, newcomers can no longer read or vote in older polls, and the names and starters of threads begun before they arrived are hidden in lists, Activity and live updates.
On a device with several accounts, what one account loaded — the @ list, member lists, profile cards, user groups — is cleared when you switch, and a recording kept for later stays with the account that made it.