It approved the research, which I don't find objectionable.

The objectionable part is that the group allegedly continued after having been told to stop by the kernel developers.

Why is that objectionable, do actual bad actors typically stop trying after being told to do so?

Which just demonstrates that these guys are actual bad actors, so blocking everyone at the university seems like a reasonable attempt at stopping them.

It's objectionable because of severe consequences beyond just annoying people. If there was a malicious purpose, not just research, you could bring criminal charges against them.

In typical grey hat research you get pre-approval from target company leadership (engineers don't know) to avoid charges once discovered.

That's not really how it works. Nobody's out there 'approving' research (well, not seemingly small projects like this), especially at the university level. Professors (all the way down to PhD students!) are usually left to do what they like, unless there are specific ethical concerns that should be put before a review panel. I suppose you could argue that this work should have been brought before the ethics committee, but it probably wasn't, and in CS there isn't a stringent process like there is in e.g. psychology or biology.

Wrong!

If you read the research paper linked in the lkml post, the authors at UMN state that they submitted their research plan to the University of Minnesota Institutional Research Board and received a human subjects exempt waiver.

A human subjects determination isn’t really an approval, just a note that the research isn’t HSR, which it sounds like this wasn’t.

It absolutely was human subject research. Try for yourself! Here's the NIH's rubric:

https://grants.nih.gov/policy/humansubjects/hs-decision.htm

for q1, the study collects data like observations of behavior, so we must answer yes.

for q2, none of the exemptions apply - it's not an educational setting, they're not sending a survey, it's not an observation of the public - they're interacting, and it's clear that these interactions are not benign - they have clear impact on the community. None of these exemptions apply.

Based on this flow, it's clear the study involves "human research".

Well it was, but not the type of thing that HSR would normally worry about.

That waiver was issued incorrectly. See my post in this same thread on why - essentially, if you do the NIH test, it's HSR.

The emails suggest this work has been reported in the past. A review by the ethics committee after the fact seems appropriate, and it should’ve stopped a repeat offence.