If a police officer orders one to move on, must the recipient comply? This article analyzes whether there is a federal constitutional right to remain, and in particular whether a police command to move on constitutes a seizure of the person for purposes of the Fourth Amendment. Although it is a close question, I conclude that the Fourth Amendment typically does not restrict a move on (MO) order, and that substantive due process only prohibits the most egregious such orders. It is a question of broad significance given the many legitimate reasons police might order persons to move on, as well as the potential for discriminatory harassment if such orders are unrestricted, and thus state and local legislatures should investigate how best to restrict the MO authority of their agents.