  Brown dwarfs may have such low masses because they are prematurely ejected
from small unstable multiple systems, while the members are still actively
building up their masses. We demonstrate that this scenario is consistent with
all currently existing observations of brown dwarfs, and propose further
observational tests. We review the status of the latest realistic numerical
simulations of disintegrating small N clusters, which show that many of the
ejected members end up with masses that are substellar, drifting away from
their birth region with velocities rarely exceeding 2 km/s.
