From the 2001 article ...Embryonic stem cells come from embryos in the first few days after fertilization and are the least specialized stem cells. The cells are extracted from the embryos inner mass, destroying the embryo in the process. The inner cell mass is surrounded by the palcental barrier that the newly conceived individual life built for itself (the woman's body builds none of the structures such as the outer layer placental barrier or the inner cell bmass), to retrieve noursihment, make gas exchanges, and protect it from being rejected by the woman's body. That placental barrier formation is an organ of exquisite design, and like all the organs of the gestating child, it is constructed by the newly conceived life.
Now, you might ask, "Why is that relevant?" well, try to think in terms of what cloning techs are intent on doing; cloning for therapies will conceive a new individual human being, life support that individual until it ages to a stage where tissue differentiation may be done to harvest specific organs or tissues, then the rest of the once alive individual will be tossed out like so much waste tissue. Folks, THAT IS CANNIBALISM, cannibalism as surely as if the techs extracted the syem cells and put them on crackers for the patient to eat! That same thing is what the ESCR people will do with the embryos, harvest the inner organs (the stem cells) and toss out the remains, the organ that breathes and feeds and protects the embryo.
If anyone would like a bit more on this issue, I've a related essay posted at my blogpage.