They were 'cowed' into silence by threats. [=they did not complain, publicly say anything, etc., because they had been threatened]
They'll be arguing about this 'till the cows come home'.
The football team was a 'cash cow' for the university.
(..) If you're in there.. You're just sick, okay? That was my first brush, with the plaque of the st century. Remember mad cow disease? Well 'Mad cow' became 'mad person' became 'mad zombie'. It's a fast acting virus, that left you with a swollen brain, raging fever and make you hateful, violent. (..)2009 Zombieland