Each man thought: one of the others is bound to say something soon, some protest, and then I’ll murmur agreement, not actually say anything, I’m not as stupid as that, but definitely murmur very firmly, so that the others will be in no doubt that I thoroughly disapprove, because at a time like this it behoves all decent men to nearly stand up and be almost heard… But no-one said anything. The cowards, each man thought.

Terry Pratchett, Guards! Guards!