Some scholars argue that the original meaning of the 8th commandment was a prohibition against stealing people. Whether kidnapping people and forcing them into slavery, or stealing those that were already slaves to someone else. Scholars say that these actions would constitute a penalty similar to that of adultery and murder. This conclusion is also drawn from the text which reads:
"If a man be found stealing any of his brethren of the children of Israel, and maketh merchandise of him, or selleth him; then that thief shall die; and thou shalt put evil away from among you" (Deuteronomy 24:7).
So, what about stealing someone's idea? Copyrights reflect a more modern thought of the nature of one's property. This is theft just as it would be if you hacked into someone's computer, downloaded their files, and distributed them for profit. Although to Moses, David and Paul the idea of copyright or patents would have been a foreign concept altogether, because mankind (thru the gift & infinite wisdom of God) has evolved this commandment cover's those concepts as if it were spoken by God only yesterday.
But let's go even deeper. In Moses day, thou shalt not steal meant more than just physically taking something that is not yours. Take Leviticus 19 for example:
"Thou shalt not defraud thy neighbour, neither rob him: the wages of him that is hired shall not abide with thee all night until the morning"(Lev. 19:13).
This scripture also translates to us in 2009. If you hire someone to do work for you, whether it is to babysit your child, to fix your roof, your car, your sink, your computer, or even type your term paper; if you have not paid what you agreed by the next morning you have robbed (defrauded) that person.