This article concerns the nature and limits of individuals’ rights to privacy over information that they have made public. For some, even suggesting that an individual can have a right to privacy over such information may seem paradoxical. First, one has no right to privacy over information that was never private to begin with. Second, insofar as one makes once-private information public – whether intentionally or unintentionally – one waives one’s right to privacy to that information. In this article, however, (...) we suggest the moral situation is more complicated than this. Rather, we argue that there is a class of public information – namely, once-private information that individuals have made public unintentionally – which remains within the scope of an individuals’ right to privacy, even when it has passed into the public domain. Significantly, this class includes any information rights-holders were unaware could be inferred from information they have made public and which they would not otherwise have wanted to be in the public domain. As we show, as well as clarifying several everyday dilemmas with regards to individuals’ privacy rights, this finding has elucidates a number of problems in the ethics of Big Data. (shrink)