The strictness varies by university. Ultimately the IRB is there to ensure safety of the participants and minimize the chance of negative consequences. A couple examples I've heard from around my university include...
A study was taking place outside. There was a chance of a bee sting occurring to the participant. The IRB required that the researcher have an epi-pen ready just in case along with any required training.
A paper used in a study had the wrong stamp on it (not the most recent IRB stamp). The document had not changed from the last time, but the rule was simple. Every document presented to the participant had to have the most recent stamp.
On a study in which it was expected that 1/2 of the participants would feel nauseous, they had to provide a place to sit, water, and small snacks.
And perhaps most importantly, you can quit any study you're participating in at any time, for any reason. Compensation is figured out ahead of time, and you're going to get lots of questions from IRB if you want to do anything to reduce the compensation for leaving part way through the experiment.
But in academia, there are also set rules and precautions governing every study. I haven't proposed any research yet but my understanding is that if your study requires collecting data from participants, the Institutional Review Board requires you to be very clear to participants about privacy and confidentiality and that you follow the guidelines to the letter.
Additionally, there are datasets only available to academics that aren't available to non-academics (i.e. journalists), which speaks to the expectation that academics be very mindful about confidentiality promises.
[0] https://github.com/fivethirtyeight/data
[1] https://github.com/BuzzFeedNews/everything