Police clashes with protesters at Columbia University have spilled over into other institutions, raising the question of how to protect free speech on campuses. Given America’s history with students’ anti-war protests going awry, should politicians be worried? Why most British voters now think Brexit was a mistake (we did warn you!) (08:53) And, could new tech protect whales from speeding ships (15:45)?Listen to what matters most, from global politics and business to science and technology—Subscribe to Economist Podcasts+For more information about how to access Economist Podcasts+, please visit our FAQs page or watch our video explaining how to link your account.  Hosted on Acast. See acast.com/privacy for more information.