Systems and methods are disclosed for distributing micro-blog posts to ad-hoc micro-blogging groups. In one embodiment, a micro-blog post of a user is obtained. A crowd in which the user is located is determined, where the crowd is a group of spatially proximate users. The micro-blog post of the user is tagged with a crowd identifier of the crowd in which the user is located such that the micro-blog post includes a crowd identifier tag. Publication of the micro-blog post including the crowd identifier tag is then effected.