The majority of the literature on Web 2.0 and social media describes several public administration benefits: building trust, achieving transparency, recruiting young professionals and realizing efficiencies. The literature argues that leadership is required to bring in cultural changes to support the use of web-based tools and links familiarity with successful adoption. Yet, little research exists exploring how these issues influence senior leaders' use of Web 2.0 and social media in a government bureaucracy. This study uses a mixed methods approach to look at senior leaders use and adoption patterns in the Ontario public service, to probe the concept of familiarity by understanding the relationship between home/personal use and work/professional use, and to contribute to an emerging public administration area. An assessment of government of Ontario Internet and intranet sites, an analysis of survey responses from 117 senior leaders in the OPS and information gathered from interviews support the study's findings.