When laud humphreys was a sociology graduate student at washington university in st. louis, he wrote his dissertation on the "tearoom trade," anonymous homosexual encounters in the men's rooms of public parks. to gather data, he acted as a lookout for his subjects, but he also surreptitiously noted license-plate numbers as the men left, so he could get their names and addresses. the next year, he picked about fifty men from the "tearooms" and interviewed them in their homes, claiming to be performing a health survey. his descriptions of the interviews made it possible for many of the men (and their families) to recognize themselves when the dissertation was published. why do many sociologists consider this research method to be unethical?