It is an vital question and the answer is yes there are so many ethical considerations in course of any online education. You may follow the follwing link to explore the answer of the question you have asked:-
Reiser, R. A., & Dempsey, J. V. (Eds.). (2012). Trends and issues in instructional design and technology. Boston: Pearson.
McMillan, J. H., & Schumacher, S. (2010). Research in Education: Evidence-Based Inquiry, MyEducationLab Series. Pearson.
Garrison, D. R. (1993). A cognitive constructivist view of distance education: An analysis of teaching‐learning assumptions. Distance education, 14(2), 199-211.
Lin, H. (2007). The ethics of instructional technology: Issues and coping strategies experienced by professional technologists in design and training situations in higher education. Educational Technology Research and Development, 55(5), 411-437.