No platform

No platform is the practice of of preventing someone — either through policy or through protest — from spreading their ideas through a particular event or website. The term generally applies to rescinding an invitation to someone asked to speak at an event (such as a guest lecture at a college). The concept apparently originates from a policy used by the British National Union of Students to prevent people they disagree with from giving speeches on UK tertiary campuses.

The idea is similar to the political action of cordon sanitaire, where a politician or political party is either unconditionally excluded from coalitions or other forms or cooperation, or even completely ignored. "No platform" is typically invoked for issues such as racism, sexism, homophobia, Holocaust denial, and so forth. As what societies find acceptable or unacceptable changes over time, so do the targets of "no platform", with 2015 seeing protests against speakers seen as transphobic or Islamophobic who consider themselves progressive as they are feminists or atheists, respectively. No-platforming is, at best, an attempt to prevent a balance fallacy, with protesters refusing to allow tacit endorsement of reactionary views.

Depending on the circumstances, the tactic can become controversial, and has been compared to book burning. Ignoring a person (or group) also means that no one is directly refuting their arguments. Some have criticized no-platforming as a form of censorship and a violation of the principles of freedom of speech and of critical thinking. The Foundation for Individual Rights in Education maintains a database of hundreds of incidents in which invited speakers have been no-platformed on college campuses, showing that the phenomenon has been "steadily increasing over the past 15 years" and is used more often by left-wingers than right wingers.

Advocates of no-platforming counter that protesters and venue holders have already heard the speaker's message, and they have decided not to extend the speaker's right to an audience that has already rejected them. The protests generally aim to raise awareness of the target's views rather than to place a blanket ban on them; the reaction from many protested is arguably censorial itself, considering they're refusing to acknowledge the right to demonstrate opposition to their views. Apparently, both sides believe that their speech is more free than others'.

Freedom of speech concerns
"No platforming" as adopted so far is not a violation of freedom of expression rights; there is no right to have a ready audience. Individuals do not have a right to speak wherever and whenever they want. For instance, newspapers are not obligated to publish every, or any, letter to the editor they receive.

In most liberal democracies, the right to publish your own newspaper, and the right to speak in a public space where speaking is permitted, are inalienable. However, private venue holders themselves also have the right to free speech and to exercise it by not promoting speech they dislike, something which is continually ignored by the people who complain about not being heard. Further, at public universities, student groups and academic departments are under no obligation to provide a platform for any particular viewpoint. Too many don't understand that their voices have been heard, but that other rights-bearing people have just decided not to give them the time of day.

An unfortunate result of "No platforming" is even more contentious debate over what exactly constitutes hate speech, and whether or not it counts as free speech. There is a contingent of people online (and sometimes even offline!), usually right-wing types and 4chan-style trolls (though some are, indeed, genuine), who are dead set on trying to hand-wave their racism, homophobia, sexism, Islamophobia, xenophobia, etc. as "Not actually hate speech", rallying behind mischaracterizations of "no platforming" as censorship to bolster their arguments.

Definitions of what constitutes hate speech have expanded in recent years; this has had the effect of making people with transphobic stances (e.g. Germaine Greer ) or who allegedly express Islamophobic ideas (e.g. Maryam Namazie ) targets for protests. These experiences ruffle the feathers of those whose approach to liberalism is out of step with the current mood of campus activists, which has led to a proliferation of editorials attacking millennials for being "coddled" in "safe spaces" or accusing them of being "anti-democratic" and "censorial". Observe how Milo Yiannopoulos, no stranger to firestorms such as Gamergate, and having coordinated an online harassment against Leslie Jones, was given a chance to speak at DePaul University as part of his "Dangerous Faggot" tour, but when the event actually went forth, he was driven out by the students and security was forbidden from helping him, as school officials were well aware of his history. When he was actually given the opportunity to speak unmolested at the University of Milwaukee, he singled out and harassed a trans student using her name and photo, thereby justifying his treatment at DePaul. He was later given an opportunity to speak at Berkeley under the dubious name of the "Free Speech Week", but was again shut down by student rioting due to his former abuse of his platform. He often characterized such backlashes as not being a chance to be heard and that if someone can change his mind then he'll tone it down, blatantly ignoring his inflammatory nature, with the added unpleasant implication that if someone cannot change his mind for whatever reason, then it's his opponents' fault and he'll go on with his hate speech without a care in the world. It wasn't until he was found to have made remarks supporting pedophilia that he was barred from CPAC and resigned from Breitbart in disgrace.

Ironically enough (or not so unironically), it's not hard to find the same people who create narratives of triggered college kids whining whenever they're called out on their bigotry. Trump's campaign ran on the premise that he was not afraid to tell it like it is whenever he made racist and sexist remarks, yet as soon as Hillary Clinton referred to these same people who ate up his hateful rhetoric as "deplorables", they were quick to jump on her for being intolerant, and after she lost the election, suggested she take up knitting. All the while, 45 was quick to constantly make inflammatory remarks about her on Twitter despite having won the election, and none of his followers batted an eye.

Effectiveness
What an extremist needs more than anything else is an enemy

In 1994, some university papers decided to run Bradley Smith's advertisement promoting Holocaust denialism, but printed a refutation on the opposition page. This was somewhat controversial, but is quite probably a more effective way to refute Holocaust denialists than ignoring them and hoping they go away. As mentioned in the free speech section above, these people will get their message out, and people uninformed of the refutations will be convinced by this. There is a caveat to refutations, however: the backfire effect, which would strengthen problematic viewpoints if they were challenged, which is among the reasons deplatforming is supported.

In a similar vein, some have also argued that it can lead to more extremism. For example, during the 1980s and 1990s, had a seat in the Dutch parliament, but was excluded from most public discourse by cordon sanitaire in both parliament and the media due to his views on immigration (which weren't even that extreme, certainly not by today's standards). Parliament members would just get up and leave whenever he spoke. This, in part, led to the rise of in the early 2000s, who was significantly more vocal on these issues than Janmaat was, and later Geert Wilders in the mid 2000s, who was even more extreme.

National Union of Students
The British has an  on no platforming, which is explicitly meant to prevent far-right speakers (defined as racists, fascists, and antisemites) from being allowed an audience at British universities in order to refuse to give their political stances credence and possibly endanger the lives of students. They also detail how this is not a restriction on anyone's freedom of speech, as the student unions are democratically deciding who they want to be allowed to talk on campus, and this in no way impinges on their ability to speak their mind elsewhere.

As of September 2014, the NUS had a blanket ban on only 5 organizations: the terrorist group Al-Muhajiroun, the racist British National Party and English Defence League, the Islamist pro-Caliphate organization Hizb ut-Tahrir, and the anti-Semitic Muslim Public Affairs Committee. The NUS enforces this by not funding speeches by these groups and not allowing their officers to share a stage with members of these groups. Individual colleges' student unions can decide to ban other speakers should they wish with internal votes.