Mobile World Congress is moving forward with an in-person event in June. Organizers are asking that everyone in attendance have a negative COVID-19 test within 72 hours of their arrival. Testing is not a sufficient way to prevent the spread of the coronavirus, particularly when tests are done that far in advance. Someone could very easily test negative, contract the virus en route to MWC, and spread the disease when they arrive. The event’s safety and security page say organizers will be “controlling crowd density” and requiring masks.