It is easy to defend the rights of those we agree with, and to insist that governments should protect their unfettered right to free expression; it is far more difficult to invoke free speech values in defence of ideas we find profoundly loathsome and inflammatory. Yet the latter is certainly a much truer test of the authenticity of one's belief in free speech.

As Glenn Greenwald has argued so powerfully through the years, defending free speech is not about protecting benign, conventional, inoffensive ideas - after all, those ideas need no protection. Rather, it is about defending those ideas that are most provocative, controversial, and designed to inspire others to act. For every significant political idea - left or right, no matter where on the spectrum it lies - has provocative potential; and if free speech can be constrained on those grounds, then a wide range of political ideas are easily subject to suppression and criminalisation - while others become sanctified - depending on the inclinations and tastes of those in power. (To take just one very mundane example - many today venerate the American founders, who believed their government had become so tyrannical and unjust that they felt justified to take up arms against it in a revolution; yet in their day, they would clearly have been many who had a vested interest in suppressing their provocative, violence-inciting speech.)

With all of this in mind, it's atrocious that France has recently arrested Dieudonné M'bala M'bala - a controversial comedian - for supposedly being an "apologist for terrorism" after he made a Facebook post that investigators decided was mocking the "Je suis Charlie" slogan, and that they thought expressed sympathy for a terrorist. Just incidentally, he made this post after attending last week's 1.5 million-strong march against extremism and in support of free speech - a march he described as a "magical moment". He might be an odious character, but whatever happened to freedom of expression?

Since that march, France has reportedly opened nearly 100 criminal cases (!) against those whose words are considered by the authorities to be "condoning terrorism". Further examples of hypocrisy: Charlie Hebdo - whose incendiary anti-Muslim cartoons have (rightly) been defended in the name of free speech - fired one of its own writers in 2009 over a single, supposedly anti-Semitic sentence. And France's most celebrated public intellectual, philosopher Bernard-Henri Lévy, demands criminal suppression of anything vaguely anti-Jewish, but when it comes to anti-Muslim rhetoric and cartoons, he has gloried in being a supposed champion of free speech. Free speech? Free suppression.

What an utter sham was that epic Parisian celebration of free speech and lofty principles of liberty! To paraphrase one of Dieudonné's fans - free speech is dead, but at least Paris gave it a pretty funeral...