1)
Who is "Amecha"?
1.
Radak: It is Yisrael, who are called Am Hashem and Nachalas Hashem - "v'Hem Amecha v'Nachalasecha" (Devarim 9:29).
2.
Malbim: Also this is the deniers' claim - Resha'im crush, afflict and kill Your nation. Why do You not do Mishpat?!
2)
Whom do they crush and afflict?