"We Will Not Be Silent" is a statement attributed to a student-resistance movement in Nazi Germany called The White Rose. It is a statement of purpose, intended to inspire acts of resistance and dissent against a corrupt government that abuses its power, and abandons the rule of law.
"We will not be silent. We are your bad conscience. The White Rose will not leave you in peace!" (Leaflet 4's concluding phrase, which became the motto of the White Rose resistance).