Algorithmic personalization drives much of the content we encounter online, from search results and movie recommendations to the ads we see and the prices we are offered. Much of this personalization saves us time and helps us find what we are looking for. However, personalization can also disadvantage individuals. Our research is aimed at improving understanding of how people think about online personalization and when people believe personalization becomes too targeted or discriminatory. By providing insight into how people feel about and understand algorithmic personalization, this research will contribute a user-centered perspective to guidelines that the Center for Democracy and Technology is developing for the fair and responsible use of algorithms.