Experiences using BDS, a crawler for Social Internetworking Scenarios ⋆ Francesco Buccafurri, Gianluca Lax, Antonino Nocera, Domenico Ursino § {bucca, lax, a.nocera,ursino}@unirc.it § Corresponding Author DIMET, University “Mediterranea” of Reggio Calabria, Via Graziella, Localit` a Feo di Vito, 89122 Reggio Calabria, Italy Abstract. In new generation social networks, we expect that the para- digm of Social Internetworking Scenarios (SISs, for short) will be more and more important. In this new scenario, the role of Social Network Analysis is of course still crucial but the preliminary step to do is de- signing a good way to crawl the underlying graph. While this aspect has been deeply investigated in the field of social networks, it is an open issue when moving towards SISs. Indeed, we cannot expect that a crawl- ing strategy which is good for social networks, is still valid in a Social Internetworking scenario, due to the specific topological features of this scenario. In this paper, we first confirm the above claim and, then, define a new crawling strategy specifically conceived for SISs which overcomes the drawbacks of the state-of-the-art crawling strategies. After this, we exploit this crawling strategy to investigate SISs in order to understand their main properties and the features of their main actors, i.e. bridges. Keywords: Social Network, Crawling Strategies, Social Network Analysis, Social Internetworking Scenarios, Bridge Users. 1 Introduction In the last years, social networks have become one of the most popular commu- nication media on the Internet [32]. The resulting universe is a constellation of several social networks, each forming a community with specific connotations, also reflecting multiple aspects of people personal life. Despite this inherent het- erogeneity, the possible interaction among distinct social networks is the basis of a new emergent internetworking scenario enabling a lot of strategic applications whose main strength will be just the integration of possibly different communi- ties yet preserving their diversity and autonomy. This concept is very recent and only a few commercial attempts to implement Social Internetworking Scenarios ⋆ This is an extended version of the paper published under the title “Crawling Social Internetworking Systems” in “Proceedings of the International Conference on Ad- vances in Social Analysis and Mining (ASONAM 2012)”, pages 505–509, Istanbul, Turkey, 2012. IEEE.