"...in conformity to the dictates of the law, Linda did not carry any weapon for self-defense. Thus, by a rather bitter irony she was required to rely for protection on the City of New York which now denies all responsibility to her...."
Riss v. New York - 1968
Cases like this, like Warren in 1981 or like Castle Rock in 2005 have come down, and yet talk to many American's and they'll honestly believe that that the police have a duty to protect them. What's worse, they falsely believe the police can and will protect them. The harsh reality is that they cannot, even if they had a legal duty to do so.
I wish every high school student had to read the Warren case before graduation. It'll make you angry, it'll make your stomach turn, and it'll hit on the idea that you can't rely on the government, that "you are all you've got." That, of course, is why it would never be required reading.