Where discrimination presents a real threat, big data need not necessary lead us to a new frontier. Existing laws, including the Equal Credit Opportunity Act and other fair lending laws, provide a number of protections that are relevant when big data is used for online marketing related to lending, housing, and employment. In comments to be presented at the FTC public workshop, Professor Peter Swire will discuss his work in progress entitled Lessons from Fair Lending Law for Fair Marketing and Big Data. Swire explains that fair lending laws already provide guidance as to how to approach discrimination that allegedly has an illegitimate, disparate impact on protected classes. Data actually plays an important role in being able to assess whether a disparate impact exists! Once a disparate impact is shown, the burden shifts to creditors to show their actions have a legitimate business need and that no less reasonable alternative exists. Fair lending enforcement has encouraged the development of rigorous compliance mechanisms, self-testing procedures, and a range of proactive measures by creditors.