...our complaints and demands should be directed toward G-d, demanding as Moshe did, "O L-rd, why have You harmed Your people... You have not saved Your people."
Similarly, we find that Gideon (the biblical judge) demanded of G-d, "If G-d is with us, why has all this befallen us? Where are all His miracles of which our fathers have told us?" G-d responded to his demand positively, telling him, "Go in this your strength [in the strength of your positive statements about the Jews] and you will deliver Israel."
Surely, after all the suffering which our people have endured in exile, particularly, after the suffering of the last generation, it is proper that we cry out to G-d over the length of the exile, and our demands will hasten the coming of the redemption.
The Lubavitcher Rebbe (grand rabbi of Chabad hassidus) (short video here) from Sichos (collected talks) Parshat Shmos 5751
BS"D - בסיעתא דשמיא