Apocryphal anecdote:
Following Stalin's death, Nikita Khrushchev gave a speech to the Politburo denouncing Stalin's policies. A few minutes into Khrushchev's diatribe, somebody shouted out, "Why didn't you challenge him then, the way you are now?"
The room fell silent, as Khrushchev angrily swept the audience with his glare. "Who said that?" he asked in a reasoned voice. Silence.
"Who said that?" Khrushchev demanded, leaning forward. Silence.
Pounding his fist on the podium to accent each word, he screamed, "Who - said - that?" Still no answer.
Finally, after a long and strained silence, the elected politicians in the room fearful to even cough, a corner of Khrushchev's mouth lifted into a smile.
"Now you know," he said with a chuckle, "why I did not speak up against Stalin when I sat where you now sit."
[I can't find the link to this just now, due to company's whitelist approach to deciding which web sites are safe]