What is the chief ethical concern concerning all the new sources of data available through new technological means like internet research?

The chief ethical concern is "Privacy".

A negative aspect of an enormous number of sources available on internet is the concerns about privacy. Web privacy includes the privilege or command of individual protection concerning the sorting, re-purposing, arrangement to outsiders, and showing of data relating to someone through the Internet. Internet security is a subset of data privacy. Privacy concerns have been enunciated from the beginnings of substantial scale PC sharing.