We analyze the liberal ethics of noninterference applied to social choice. A liberal principle capturing non-interfering views of society and inspired by John Stuart Mills conception of liberty, is examined. The principle captures the idea that society should not penalize agents after changes in their situation that do not affect others. An impossibility for liberal approaches is highlighted: every social decision rule that satisfies unanimity and a general principle of noninterference must be dictatorial. This raises some important issues for liberal approaches in social choice and political philosophy.