The Shem MiShmuel asks: How could Avraham ask G-d to be compassionate on the wicked people of Sodom when they were systematically victimizing others? Isn't compassion for the wicked tantamount to cruelty for their would be victims? The answer is that Avraham actually had a strategy in which he felt that the people of Sodom could be reformed through the power of compassion.
