Despite their ubiquity online, personalization algorithms and the associated large-scale collection of personal data have largely escaped public scrutiny. Yet policy makers who wish to introduce regulations that respect people's attitudes towards privacy and algorithmic personalization on the Internet would greatly benefit from knowing how people perceive different aspects of personalization and data collection. To contribute to an empirical foundation for this knowledge, we surveyed public attitudes using representative online samples in Germany, Great Britain, and the United States on key aspects of algorithmic personalization and on people's data privacy concerns and behavior. Our findings show that people object to the collection and use of sensitive personal information and to the personalization of political campaigning and, in Germany and Great Britain, to the personalization of news sources. Encouragingly, attitudes are independent of political preferences: People across the political spectrum share the same concerns about their data privacy and the effects of personalization on news and politics. We also found that people are more accepting of personalized services than of the collection of personal data and information currently collected for these services. This acceptability gap---the difference between the acceptability of personalized online services and the acceptability of the collection and use of data and information---in people's attitudes can be observed at both the aggregate and the individual level. Our findings suggest a need for transparent algorithmic personalization that respects people’s data privacy, can be easily adjusted, and does not extend to political advertising.