Wit has always been a weapon of mass campaigning. Sometimes there is no better way to expose society's ills than to encourage us to laugh at them. Comedians with social consciences employ humour to deal the deadliest of blows to pomposity and prejudice.
But in these times of all-seeing media, the comedian is more powerful than ever. We are now as familiar with the targets of comedians' jokes in other countries as we are in our own. Michael Moore's acerbic observations about his homeland have turned him into an omnipresent commentators on US affairs. Tens of millions have seen Bowling for Columbine, his film on US gun culture - many thousands more than would have tuned into a TV documentary about the issue.
And he is by no means alone. Comedians with a talent for making us think, as well as laugh, now write for national papers and political weeklies, appear in TV debates and radio shows. We respect them because, by showing us how insane we are, they appear to us to be very sane indeed.
What's more, we listen to what they say. The fact that one of Britain's most influential columnists, Polly Toynbee, recently devoted an entire piece to rubbishing an episode of Channel 4's Bremner, Bird and Fortune is evidence enough that comedy hits where it hurts. In the build up to the Iraq war, when both government and opposition seemed oddly out of step with the prevailing views of the population, Bremner's show was one of the few places where you could actually find a serious and meticulously researched critique of world affairs.
Have campaigners spotted the rising influence of comedians? The voluntary sector is not renowned for its sense of humour. Our image is more po-faced than playful, more worthy than witty. We work, of course, on very serious issues. The plight of the most vulnerable in society is no laughing matter.
We don't invite laughter but action; we prefer to ask comedians to do star turns at our fundraising events, rather than at our conferences.
Comedy and campaigning may feel to us to be a strange mix, but then perhaps we have underestimated just how influential humour can be.