Why are some research unethical?
All types of research carry some form of risk to research subjects. These risks could come from the procedures that are used, or the personal information that is collected in the process. Some research are riskier than others.
However, the presence of risk itself is not an absolute deterrent to conducting research, nor does it directly render a research unethical.
The ethics of using people as subjects of research lies heavily in ensuring the safety and welfare of research subjects, but even more importantly, in the way people are treated.