The goal of the Semantic Web is the publishing and sharing of semantically annotated data. As a result, machines are able to understand and process such data in order to enhance and increase the tasks that can be performed on today’s Web. In the last years the Semantic Web has become more and more social, that is, such data does not anymore consist only of business services and products but it increasingly includes information about people, their relationships with others, what they do, believe and like. Semantic Web technologies are used to ease and increase communication and information exchange on the Web, and therefore interlinking various sources of distributed data. For instance, efforts like FOAF and SIOC provide the ability to merge social networks and to exchange socially-created data among different platforms and providers. At the same time, Semantic Web technologies have been advanced and currently numerous knowledge repository are exposed to the public, following the Linking Open Data movement.
Naturally, the general goal of combining distributed semantically annotated knowledge raises issues of trust and privacy. For example, information gathered from the Semantic Web shall be trusted before it is further processed. Also social activities empowered with semantic technology like social networking, blogging, desktop or resource sharing require privacy to be ensured. In many cases, information about a person is not published by herself, but by others, therefore possibly risking a user’s privacy1. Additionally, once it is published, not only a reader of such information should decide whether it is to be trusted and if yes, to what degree, it is also a question of how such information may be used, and whether it may attempt against other people’s privacy2.
Trust and Privacy are needed both in terms of publishing and consuming data: ”which sources should I trust?”, ”how to ensure that this information is valid?”, ”does it really come from someone I know or an authoritative source?”, ”how to share part of my identity only to trusted people?”, or ”how to ensure the information I disclose will not be misused or responsible will be made accountable?” are questions that need to be answered now while more and more people use the Semantic Web for socializing, for sharing personal data, and for general information exchange.
Semantic Web technologies have reached a status where they influence our daily lives. On the one hand, applications for sharing semantically annotated pictures, blogs, and videos as well as semantic-enhanced social networking platforms are present. On the other hand, the so-called Web of Data with its thousands of billions of triples is leaving its research prototype status. Applications using 1 an example for this can be found at http://www.smh.com.au/news/technology/ virgin-sued-for-using-teens-photo/2007/09/21/1189881735928.html 2 for an example, see http://www.washingtonpost.com/wp-dyn/content/article/ 2007/11/29/AR2007112902503.html Semantic Web technologies start to arise and to be used by a large number of users. However, although trust and privacy play a crucial role in its final development and adoption, in most of the running systems and research prototypes no or not sufficient solutions to address these topics are considered. The Semantic Web as well as the Social Web has reached a state where those issues have to be addressed seriously in order to become reality.
The First International Workshop for Trust and Privacy on the Social and Semantic Web (SPOT2009) brings together, among others, researchers and developers from the field of Semantic Web, the Social Web, and trust and privacy enforcement. It provides the opportunity to discuss and analyze important requirements and open research issues for a trustful Semantic Web.
We are grateful to the members of the Program Committee of SPOT2009 for their support. We would like to thank all the authors who submitted their work for their interesting contributions. Further on, we thank Prof. Piero Bonatti for being available as invited speaker and, last but not least, the European COST Action IC0801 ”Agreement Technologies” for supporting the invited talk. May 2009 Michael Hausenblas
Philipp K¨arger
Daniel Olmedilla Alexandre Passant
Axel Polleres Organizing Committee of SPOT2009