> They are not owned by Reddit.

You sure about that? I would bet that if reddit requested google take down the data, google would comply.

If not Reddit, then who owns it?

The individual users own the content they create. The Reddit TOS gives Reddit a broad license to use it but the content itself is owned by the users.

So who owns the dataset aggregated from all users?

More importantly, did the people running analysis on this dataset get explicit permission from the European post authors as required by the GDPR?

I mean the BQ datasets aren't managed by Reddit, they're sourced from pushshift, so Reddit wouldn't immediately take them down.

Whether or not Reddit could file a DMCA complaint to force it down is up for debate.