On Pedagogical Tools: Is swearing or chewing someone out a viable method? I am well aware of the decorum and tact expected of professors, teachers and TA's. But in the rare instances where an instructor swore to emphasize a point, the class and I remembered the outburst clearly and with vivid detail.

Without going into detail the gist of the situation was that a group failed to prepare for a big presentation that was scheduled well in advance and decided to 'wing' the presentation with a last-minute powerpoint slide of uncited material.

The professor, having lost his cool, chewed out the group in front of the class with a string of f-bombs stipulating how stupid and idiotic it was that the group not only failed to plan but planned to fail. The professor subsequently failed the group for the project. This was a point of discussion and remembrance whenever the class was talked about after the semester was over.

Nevertheless, the learning moment was accomplished and no one after the incident ever failed to produce viable work afterwards.

With this said, what are the ethical, moral, legal, and interpersonal considerations here that I am unaware of?
It's one thing to criticize the group for poor work - I've witnessed this and it is fully called for to say that the group has come unprepared and has underperformed. It's a very different thing for a professor of all people to lose their cool and use expletives in front of students. I am in Europe and this is poor personal control, poor personal culture, and by all means unacceptable behavior within a classroom. No matter how bad a group - they will deservedly get a bad grade in the end - but you can simply never - and it is never acceptable to lose your cool like that and pretty much insult students  in front of their peers. In school we get grades, not expletives. This is never acceptable. Never.