This paper examines the rhetoric of Twitter.com in order to gain insight into the company's normative selfunderstanding, or ethos. From a business ethics perspective, we analyze Twitter's ethos in relation to debates around democratic communication and Corporate Social Responsibility (CSR). Partly thanks to its CSR strategy, Twitter has acquired the critical mass of users necessary to successfully establish a robust and financially viable social network. Despite its success, however, we argue that Twitter does not sufficiently address three ethical implications of its strategy: (1) from an ethical perspective, Twitter mainly seems to employ an 'instrumental CSR' ethos which fails to properly recognize the moral rights, responsibilities, and strategic challenges of corporate actors with regards to their stakeholders; (2) this issue becomes all the more pressing because online social networks to a certain extent have taken on the role of quasi-governmental bodies today, regulating what their users can and cannot do, thus raising questions of accountability and legitimacy; and (3) in Twitter's case, this leads to normative tension between the site's rhetoric, which is centered around civic motives, and the way its Terms of Service and licensing policies seem to favor its commercial stakeholders over its non-commercial ones.