To challenge them is to court death.
9 seconds sound clip from the The Avengers (2012) movie soundboard.
You can hear this line at 02:15:40 in the Blu-ray version of the movie.
Quote context
[...]
- If we get into a situation like this again, what happens then?
- Are you really sure about that?
- I am.
- Why?
- Humans. They are not the cowering wretches we were promised. They stand.
- They are unruly, and therefore cannot be ruled.
- To challenge them is to court death.
[...]