My dad served in Vietnam as an MP (military police) after he was drafted. He has never talked about it much, but I can distinctly recall the handful of times he did.
One time was during the 2nd Iraq War. The Abu Ghraib sandal had just broke, where US soldiers were caught torturing and sexually humiliating/abusing prisoners by stripping them, tying them up, violating them with objects, etc.
My mom saw all the news reports on cable TV and she was outraged