But it's sooo convenient!
More seriously, not sure if data harvesting isn't already possible for those of us who use hashtags and post often enough.
And not so seriously, if gup.pe groups are a bad thing, perhaps they can motivate the support of groups in core mastodon, with whatever enhancements defend against the problem.
It's not obvious to me how I can talk in public about things which interest me without leaving a trail of the things which interest me.
@EdS @deejoe @kensanata Public posts with hashtags are certainly the most visible form of communication here. My posts are almost exclusively unlisted or followers-only, but my unlisted posts are visible on my profile, so still quite easy to scrape.
It's not just a privacy issue, though. It's also an issue of centralization of control. Who gets a say in what gets to be communicated via groups? Who gets a say in what groups get to exist?
"I appreciate SDF but it's a general-purpose server and the name doesn't make it obvious that it's about art." - Eugen Rochko