T. Morel, Norberto Castro, Luca Fossati, Swetlana Hubrig, N. Langer, Norbert Przybilla, Markus Schöller, Thorsten Anthony Carroll, Ilya Ilyin, Andreas Irrgang, Lida Oskinova, Fabian R. N. Schneider, Sergio Simon Díaz, Maryline Briquet, Jean-Francois González, Nina Kharchenko, M.-F. Nieva, Ralf-Dieter Scholz, Alexander de Koter, Wolf-Rainer Hamann, Artemio Herrero, Jesus Maíz Apellániz, Hugues Sana, Rainer Arlt, Rodolfo H. Barbá, Polly Dufton, Alexander Kholtygin, Gautier Mathys, Anatoly E. Piskunov, Andreas Reisenegger, H. Spruit, S.-C. Yoon

• The B fields in OB stars (BOB) survey is an ESO large programme collecting spectropolarimetric observations for a large number of early-type stars in order to study the occurrence rate, properties, and ultimately the origin of magnetic fields in massive stars. As of July 2014, a total of 98 objects were observed over 20 nights with FORS2 and HARPSpol. Our preliminary results indicate that the fraction of magnetic OB stars with an organised, detectable field is low. This conclusion, now independently reached by two different surveys, has profound implications for any theoretical model attempting to explain the field formation in these objects. We discuss in this contribution some important issues addressed by our observations (e.g., the lower bound of the field strength) and the discovery of some remarkable objects.