Additional controlled research surveys on the makeup of online users and their backgrounds, SES, educational levels, and level of pathology is needed, though. Surveys to date, for instance, have not asked questions which helped determine the makeup of whether the distributions of online users which have diagnosed medical or mental health problems is the same as the distribution of people in the real world. Without such basic information, subjects from this population may not be representative of the real-world population. I highly encourage any professional interested in conducting research into online behavior to subscribe to a mailing list I setup to discuss such issues. This brings up another interesting problem with conducting online research.
Many researchers are interested in studying online individual and group behavior.
Many researchers are coming online and conducting what they call in vitro studies of online groups. These studies are unethical and wrong if they have not yet first obtained that group's consent to study their behavior and interactions. IRBs should be attuned to these issues and reject any study which does not include fully informed consent of all potential participants of that group. I don't know of a single online group which appreciates a researcher coming into the group to eavesdrop on their conversations and interactions. Yet researchers have done this in the past online simply because they could.