Magnetised space plasmas can often be modelled as a collection of strings, which correspond to magnetic flux tubes. If such a tube/string happens to fall into a Kerr black hole, then the leading portion loses angular momentum and energy as the string brakes, and to compensate for this loss, momentum and energy has to be radiated to infinity to conserve energy and momentum for the tube. Inside the ergosphere the energy of the leading part can be negative, and the rest of the tube then extracts energy from the hole in the form of a torsional Alfvén wave. Reconnection comes into play during the next bursty phase, releasing Maxwellian stresses and producing a relativistic jet.