Some time ago there was dismay on Mastodon (and Pleroma ?) instances about data scraping. Before that happened there were privacy concerned people automatically deleting their own toots, limiting them for example to the latest toots for thirty days. With Lemmy things are different since Lemmy is a link aggregator rather than micro blogging, and Mastodon has boost option (Called replay with Pleroma ?). However deleting your older comments (but not posts) automatically would be really nice for privacy reasons.
I blocked the IP ranges for archive.org. Archive.org was the first stop of my bullies and stalker to fetch data from my homepages. It’s also possible to send them an email with a removal request. Their service for removal is not the fastest, but it’s ok.