Granting a group freedom of expression does not lead to an obligation to give them a platform. But the absolute restriction on anyone doing so is wrong in principle and counterproductive in practice.-: from George Eaton's blog :-
[I]t is John Stuart Mill’s imperishable On Liberty that best distils the indispensability of unrestrained argument. It is only in conflict with opposing views, the great liberal argued, that we fully understand and refine what we ourselves believe. It keeps our principles alive and dynamic. Without this open conflict the reasoned views of one generation can ossify into the prejudice and dogma of the next. Anti-racist and anti-fascist views become held not because they have been forged in the heat of dialectical exchange, but merely because they represent the received wisdom of the age.Unfortunately, unthinking conformity is the default state. For the most part, people find being safe within the herd extremely comforting. And herds are wont to trample on dissent.