Given a symplectic manifold, consider the supremum of the minimal actions of regular closed coisotropic submanifolds of a fixed dimension. This defines a symplectic capacity. It follows from a leafwise fixed point result for Hamiltonian diffeomorphisms that the capacity of the standard symplectic cylinder is bounded above by pi. On the other hand, using a Lagrangian submanifold considered by M. Audin and L. Polterovich, one obtains a lower bound for the ball. A version of the capacity which is based on spheres, turns out to be discontinuous in dimension four. This answers a question by K. Cieliebak, H. Hofer, J. Latschev, and F. Schlenk.