Here's a few famous ones, most of which are of course a few years old since government agencies tend to move slow but more recent ones will get what's coming for them.
https://www.theguardian.com/technology/2022/nov/28/meta-fine...
https://ico.org.uk/media/action-weve-taken/mpns/2618524/marr...
https://en.wikipedia.org/wiki/British_Airways_data_breach#Co...