I think there are two common themes. One is the whistle-blower's motive for speaking out. That's universal. Whether it's something we put a positive or a negative value judgment on, they had to exercise those free speech rights in order to be true to themselves. If they hadn't acted on their knowledge, for better or worse, for good or bad reasons, it would have haunted them for the rest of their lives. It's something intrinsic to citizens of a free society.
The second common theme is that these were people challenging abuses of power that could not withstand independent scrutiny. That's why whistle-blowers are so effective when they work with us. They're exposing misconduct that can only be sustained if it remains secret and people don't know about it. That's what makes this law so powerful in terms of its potential to have an impact for change. In my opinion, since the time of religious leaders like Jesus and scientific leaders like Galileo and Copernicus, whistle-blowers have been the people who have changed the course of history.