Standard rules of ethics for experiments on human subjects say that (with a few exceptions) subjects should always be informed about the study. If that changes the subjects' behavior such that the study is no longer valid, it's the researcher's obligation to come up with a better design that works in the face of informed consent, or to give up and study something easier.
It's been fairly well established that "I wanted to learn something" isn't an adequate excuse for doing things to people without informing them or receiving their consent.
Before you talk about peoples' "clueless 'ethics'", you might want to read the professional standards of the field, for example the American Psychological Association's Ethics Code. The section on "informed consent to research" is here: http://www.apa.org/ethics/code/index.aspx?item=11#802
It's been fairly well established that "I wanted to learn something" isn't an adequate excuse for doing things to people without informing them or receiving their consent.
Before you talk about peoples' "clueless 'ethics'", you might want to read the professional standards of the field, for example the American Psychological Association's Ethics Code. The section on "informed consent to research" is here: http://www.apa.org/ethics/code/index.aspx?item=11#802