We will review the theory of Brauer-Manin obstructions to the Hasse principle, then discuss what is known about the Hasse principle for cubic threefolds with isolated singularities. In particular, Shepherd-Barron classified 9-nodal cubic 3-folds and proved that the only obstruction to the Hasse principle for these 3-folds is the Brauer-Manin obstruction. Building on the work of Shepherd-Barron, we write down an explicit example of a 9-nodal cubic 3-fold violating the Hasse principle. This is work in progress joint with Anastassia Etropolski and Marta Pieropan.