Penumbras?

The Roe v. Wade decision of 1973 used the "penumbras" of the Bill of Rights to justify their decision.
A penumbra is an area of partial illumination, as shown in the picture to the left. For example, if the sun is the Bill of Rights, the earth - or the light illuminating the earth - is everything the Bill of Rights addresses as a right the people of America possess. The shadows behind the earth represent things that citizens do not have a right to do, and the gray area is a sort of in between - an area that the Bill of Rights does not necessarily address or does not technically say that the people can't do it.
I do not think that it is right that we can justify rights of the people using the penumbras in the Bill of Rights. The reason I say this is because when you do not give people a clear, black and white list of what they can and cannot do, there are always going to be people out there that try to get away with as much as possible. I believe when you begin to take the gray area as acceptable, it is hard to know where the gray stops and where the black begins.