  The Julia-Toulouse mechanism is used to show that the topological Abelian BF
term may be induced by the condensation of electric charges. As an application
we discuss the subtle question of including consistently magnetic defects into
the Maxwell-BF theory in a way to avoid the usual problems of current
conservation, charge quantization, Elitzur's theorem violation and the reality
of the Dirac brane, produced by the non-minimal coupling. We also discuss a new
way of obtaining the Dirac's veto, which is based on the so-called Dirac brane
symmetry.
