What does "my brother's keeper" mean?

We just launched the Mobile Find "King James Bible" channel. It's the whole bible, and you can search it in a heart beat.

The King James Bible is in the public domain. You can get the whole thing from Project Gutenberg.

I pointed out to Derek that web sites let you search among bible quotes, which is a small subset. Why not search the whole bible?

He said it's because the bibles that people like are copyrighted. Even though it's free, people don't like the King James version. Why not? Because the newer versions are put into modern language.

Here's an example from Genesis 4:9 for both the King James and New International versions.

King James: Then the LORD said to Cain, "Where is your brother Abel?" "I don't know," he replied. "Am I my brother's keeper?"

New International: God said to Cain, "Where is Abel your brother?" He said, "How should I know? Am I his babysitter?"

Hilarious.