Britain's 5.5 million Twitter users are younger than average members of the public, slightly more likely to vote Labour, and distinctly more liberal, according to a survey published today.
They are also more likely to live in London, less likely to live in the north of England, and marginally more likely to belong to a lower social class.
The YouGov poll may help to explain why libertarian campaigns appear to flourish on Twitter.
Users of the social networking site recently rallied to support the Guardian when lawyers representing Trafigura tried to stop the paper reporting a parliamentary question, and hounded the Daily Mail writer Jan Moir for her allegedly homophobic remarks about the death of Stephen Gately.
But the findings, which are published in the latest issue of Prospect magazine, do not depict Twitter users as inherently leftwing. They are more likely than average members of the public to think that there is nothing wrong with executives earning multimillion pound salaries and large bonuses.
YouGov surveyed 2,024 adults, of whom more than 200 use Twitter, and compared the views and characteristics of the Twitterati with those of the sample as a whole. The biggest difference emerged when respondents were asked about civil liberties. The proposition that protecting civil liberties is more important than giving the police more anti-terrorist powers was backed by just 33% of the public, but by 43% of Twitter users.
Some 56% of all respondents agreed with the claim that ordinary white men are often the biggest victims of discrimination. But only 45% of Twitter users accepted this.
Twitter users are younger than average adults (46% are under 35, compared with 29% of all respondents) and more likely to live in London (18%, compared with 13%). They are also slightly less likely to vote Conservative (38%, compared with 41%) and slightly more likely to belong to a lower social class (48%, compared with 45%).
YouGov discovered one other key difference. Most users find Twitter either "very worthwhile" or "mildly useful". But 39% of all respondents said that it "dumbs down" the way people communicate and 76% of them said they had no interest in using it themselves.