suppression

prohibition

is an act that generally tends to strengthen what it would prohibit.

Laws to suppress tend to strengthen what they would prohibit. Frank Herbert

is informal --- no government suppresses thought and speech as effectively as your friends and neighbors do.

No government suppresses thought and speech as effectively as your friends and neighbors do.

is never successful --- Every suppressed or expunged word reverberates through the earth from side to side.

Every suppressed or expunged word reverberates through the earth from side to side. . . . .

is likely to cause backlash --- A cat contained becomes a lion.