I remember a while back reading a thing where basically there were bots out there essentially scraping entire chat logs without its users really being aware of this. There's probably also a lot of stuff going around with identity (like people making bots that look like official ones but aren't) etc.

I get people complaining about this situation, but there is a gradient of access between "no content access whatsoever" and "the bot can see everything". Slack's API does a pretty good job of making some of this work