https://www.techdirt.com/articles/20211006/15054247715/content-moderation-case-study-twitters-self-deleting-tweets-feature-creates-new-moderation-problems.shtml

Summary: In its 15 years as a micro-blogging service, Twitter has given users more characters per tweet, reaction GIFs, multiple UI options, and the occasional random resorting of their timelines.

The most recent offering was to give users the option to create posts designed to be swept away by the digital sands of time. Early in 2020, Twitter announced it would be rolling out "Fleets" — self-deleting tweets with a lifespan of only 24 hours. This put Twitter on equal footing with Instagram's "Stories" feature, which allows users to post content with a built-in expiration date.