expression

It should be restricted.
Certain human experiments may harm the society. For example: the Japanese did to the Manchu people of Chinese. They tested how bomb explosion can affect human flesh, reattach limbs person to person, often this people are kept alive for future experiment.
If there is a human experiment, it should be accordingly and humane. Today, there are human experiment involving test subject, usually in the branch of medicine. As long as it follows the rule, then it's perfectly fine.

You can explore the subject further in regards to the medicine experiement in human.
Some ideas:
The United States claims to be the world leader in medicine. But there's a dark side to western medicine that few want to acknowledge: The horrifying medical experiments performed on impoverished people and their children all in the name of scientific progress. Many of these medical experiments were conducted on people without their knowledge, and most were conducted as part of an effort to seek profits from newly approved drugs or medical technologies.

To truly understand how this mass experimentation on modern Americans came into being, you have to take a close look at the horrifying history of conventional medicine's exploitation of people for cruel medical experiments.

Human experimentation -- that is, subjecting live human beings to science experiments that are sometimes cruel, sometimes painful, sometimes deadly and always a risk -- is a major part of U.S. history that you won't find in most history or science books. The United States is undoubtedly responsible for some of the most amazing scientific breakthroughs. These advancements, especially in the field of medicine, have changed the lives of billions of people around the world -- sometimes for the better, as in the case of finding a cure for malaria and other epidemic diseases, and sometimes for the worse.

2009-01-09 05:18:47 補充：
However, these breakthroughs come with a hefty price tag: The human beings used in the experiments that made these advancements possible. Over the last two centuries, some of these test subjects have been compensated for the damage done to their emotional and physical health, but most have not.

2009-01-09 05:19:09 補充：
Many have lost their lives because of the experiments they often unwillingly and sometimes even unwittingly participated in, and they of course can never be compensated for losing their most precious possession of all: Their health.