"And where once you had the freedom to object, to think and speak as you saw fit, you now have censors and systems of surveillance coercing your conformity and soliciting your submission."
--V (V for Vendetta)
Ideas are fungible and, like goods, naturally trade on markets. When these markets are free and unhampered, ideas trade liberally between buyers and sellers seeking to mutually benefit from the exchange. Competing ideas are considered, discussed, revised. Some ideas win, others are rejected.
Those fearful that their ideas will be rejected may be tempted to interfere with free, uninhibited exchange of thought. They seek to regulate trade by restricting what can be said and by whom. They want to restrict access to venues for broadcasting ideas. They twist words, quote out of context, report events in incomplete or dishonest manners. They try to shout down speakers with differing viewpoints.
When ideas can't compete on their own merits, then the purveyors of those ideas will seek to shut down markets where competing designs are likely to be judged as superior.