Are there any examples of ruthless behavior in everyday life, or is it mostly something we see in movies and stories about tyrants and criminals?

Is "I don't do business over the phone. Please write to me and I will consider it" the best polite way of discouraging cold callers. The don't have your address so can't write but don't want to admit it, so are happy to end the call?
What makes some people in business and politics willing to lie and deceive, and why don’t more of them face consequences for their actions?