Freedom of speech is silenced through the use of labels (pick your -ist or -phobe) being unfairly assigned to those who don't agree with your narrative to more aggressive tactics like harassment, bullying, doxing, blackmail, threats, and outright violent assaults. Groups like BLM and Antifa and their like-minded allies use these tactics to silence, brow beat, and character assassinate any who dares fall out of line with their (many of the times false) narrative or political position. Private citizens and even public officials (e.G. IRS harassment scandal and accusations of a "muslim ban" by congressional Democrats in refugee immigration vetting to name a few) are both guilty. There simply is no discourse or debating of the merits of differing positions/ideas. There is an active push to not only NOT seek the truth, but to redefine truth to fit a narrative regardless of opposing facts. Facts simply don't matter anymore and the concept of 'the pursuit of the truth' is no longer a virtue but has been demonized. Truth should be the aim for everyone regardless of your feelings or position. This "you're either with us or you're a fascist" false dichotomy has to stop. "Sunlight is the best disinfectant" meaning the more information and transparency we have, the better we will be able to obtain the truth. These anti-freedom of speech/safe space/hate-speech minded folks have to rely on darkness and keeping people in the dark by providing less knowledge and facts while manipulating the language of discourse to control information available to the public. Without the necessary facts in the light of day, the truth will always be obfuscated when free speech (especially unpopular speech) is not freely allowed and evaluated against the facts.
When people are allowed to speak freely you have no control over what they say. Hateful comments can be made and rumours can spread quickly. These rumours can become much larger. They can evolve into 'fake news'. A particularly vicious piece of fake news could be disastrous and end up in government shutdowns and other hugely bad consequences.