An example of something that's not human subjects research would be emailing people who have websites and asking about their privacy policy.
An example of something that is human subjects research would be emailing people who have websites and asking what inspired them to start a website.
I realize that may seem like a subtle difference, but it's an important distinction from an IRB perspective. For reference, and because a lot of people seem confused on this thread, here's what the human subjects research training at my university says about this...
"...some research that involves interactions with people does not meet the regulatory definition of research with human subjects because the focus of the investigation is not the opinions, characteristics, or behavior of the individual. In other words, the information being elicited is not about the individual ('whom'), but rather is about 'what.' For example, if a researcher calls the director of a shelter for battered women and asks her for the average length of stay of the women who use the shelter, that inquiry would not meet the definition of research with human subjects because the information requested is not 'about' the director. If the researcher interviewed the director about her training, experience, and how she defines the problem of battering, then the inquiry becomes about her - and therefore 'about whom.'"