There have been cases of wars which include biochemical weapons. If science is left to grow with no limit, the world, in a few decades, would have created mutated life forms that 'does not deserve life'. Not only that, technology could create new weapons of mass destruction. An example would be the atomic bomb that was used in World War II. There have also been various arguments that science is all about finding the truth. However, many have failed to realize that science does not only find answer, it also opens up more questions, leaving scientists in a never-ending quest of knowledge. Another factor why science should be regulated is that there could be cases of human cloning. It is ethical to believe that human cloning in itself is a taboo, which gives reasons why it is banned in the world.
If we could research and experiment on any subject without causing harm to anyone, we probably would progress at an unprecedented rate. However, is it worth it. There are some aspects of science while intriguing are not ethically possible. For example the topic of Human Cloning is so immoral that few scientists would dare travel down its dark path. We have a moral responsibility as humans to put people over science.
Most scientist would not dare to claim Earth was not the center of the Universe centuries ago. Science gets to the truth and helps move the social attitudes/moralities. It should not be another way around as ignorance would then rule. You an use anything for good or evil, including human cloning. But its good to have an option.
Science should not be regulated because the point of science is to find the truth in nature. If you put constraints on what can or cannot be explored you are impeding that quest for truth. Scientists must have the freedom to explore wherever their research takes them and not be beholden to arbitrary regulations.
The primary abuser of scientific research tends to be corporations seeking to gain profits while minimizing losses. The quick answer would be to eliminate corporate funding from research, but that would end up eliminating funding from most projects currently going on. The next answer would be to limit corporations from abusing new technologies, but this is a band-aid fix because we would not be able to fully regulate business practices concerning technology that is new and not necessarily well-known. Personally, I believe we need people to make decisions not driven primarily by monetary gains. This, however is based on an optimistic outlook on people. But regulating science would only hinder advancement of society and decrease the amount of help we can give to people in need.