As the Internet has changed communication, commerce, and the distribution of information, it is also changing psychological research. Psychologists can observe new or rare phenomena online and can do research on traditional psychological topics more efficiently, enabling them to expand the scale and scope of their research. Yet these opportunities entail risk both to research quality and to human subjects. Internet research is inherently no more risky than traditional observational, survey or experimental methods. Yet the rapidly changing nature of technology, norms, and online behavior means that the risks and safeguards against them will differ from those characterizing traditional research and will themselves change over time. This paper describes some benefits and challenges of conducting psychological research via the Internet and offers recommendations to both researchers and Institutional Review Boards for dealing with the challenges.