If your company uses the Microsoft ecosystem, have a look at the search function in Delve or SharePoint or whatever the fuck they're calling the shared employee document repository this week.
At one point, I don't know if you still can, the search would scan meeting transcriptions if the organizer fucked up the privacy settings.
I searched for naughty bigboy words and came across a transcript of two employees (who had since left the company) just absolutely shittalking a manager.
Besides some hilarious typos I also found some old chat logs where I was using some colourful language. Deleted that. Hopefully it's proper gone and HR won't find it.
This is true, but AI can be used as a tool to summarize and otherwise distill a massive amount of information to a form that someone can make sense of. It was probably cost prohibative to go through this data before or making specific snooping tools.