What is the point of speaking up?

When confronted by egregious human rights abuses, or war crimes and crimes against humanity including genocide, does speaking up make any difference? Especially if words are not followed by action? There are at least four reasons why it is still crucial to speak out, and how doing so can be effective. Also what matters is the pedestal of the speaker. The higher that is, the greater their responsibility to speak out. Of course,the rhetoric-reality gap is often vast and it is easy to get cynical. But silence or ambivalence kill and destroy much more. So, speak up clearly and loudly to wake up even the dead.