@SarahPalinUSA Peaceful New Yorkers, pls refudiate the Ground Zero mosque plan if you believe catastrophic pain caused @ Twin Towers site is too raw, too real (18 July. Fanning flames of controversy) / AP
The trouble 140 characters can cause...

Watching your private musings unwittingly broadcast to the world can be mortifying, as any US diplomat will tell you. And yet, all year, celebrities were lining up to make fools of themselves in the public arena. Twitter was their tool.

As early as February, hacks were making hay with the travails of televisual family man Vernon Kaye, who had been caught sending racy tweets to a Page 3 girl. Discreet enough to conduct the exchange via the site's private direct messaging service, he'd neglected to consider one crucial detail: that the Page 3 girl in question was, by definition, an employee of The Sun. There was added irony in Kaye's digital dalliance. His wife Tess Daly was about to publish her book The Baby Diaries: Memories, Milestones and Misadventures – an account of their blissful family life. It duly flopped.

In November, the Kaye story was surpassed by that of Jason Manford, panel quiz comedian and new host of The One Show. The married Manford was cornered – by the same newspaper, as it happens – after bombarding a female fan with private tweets. He'd begged the busty young woman for ever more salacious snaps of herself with all the eager desperation of a teenage boy calling a premium rate sex line. (She had obliged.)

December brought a higher class of Twitter scandal, when it emerged that Elizabeth Hurley and Shane Warne had been enjoying each other's company at racecourses and London restaurants. That they were especially close became clearer upon examination of their many tweets – including Hurley's transparently suggestive assertion that her pet spaniel, "Sammy", was to keen to nuzzle the Aussie spin-bowler's neck. "Sammy," read the 140-character come-on, "sends you a special lick and says he'd like to put his silky head on your shoulder." A more sober Hurley took to Twitter when the story broke, announcing that she and her husband Arun Nayar had, in fact, been separated for months.

Meanwhile, Warne's cricketing chum Kevin Pietersen had been tweeting merrily about borrowing the Australian's yellow Lamborghini. Until, that is, he was fined and given three points for doing 75mph in a 62mph hour zone just outside Melbourne. It was not Pietersen's first embarrassing run-in with the microblogging service. In August, when he wasn't hitting double centuries, he was dropped from England's squad for the Twenty20 and one-day internationals against Pakistan. In an apparently mis-sent direct message, he informed his many followers of his anger. "Its a fuck up!! [sic]", he exclaimed. It certainly was: Pietersen was disciplined by the England and Wales Cricket Board for his indiscretion.

Elsewhere, Welsh rugby forward Jonathan Thomas was forced to apologise after tweeting a bit of homophobic banter with his fellow Ospreys lock Ian Evans – soon after his celebrated Wales team-mate Gareth Thomas had come out, supposedly improving the climate for gay sportsmen.

Among the more entertaining football tweeters is exclamation mark-prone Derby captain Robbie Savage, whose Twitter profile describes him thus: "41st all time prem[iership] app[earance]s and 3rd most booked!! Overachiever!!!! The peoples pundit!!!" In October, Savage took to Twitter to defend the extortionate wages of his footballing colleagues. The nuances of his argument were ignored by the Daily Star, however, which chose to focus instead on his tweeted boast that trick-or-treaters would be deterred by the lengthy driveway leading to his £2.5m Cheshire mansion. Incensed, Savage announced that he was leaving Twitter for good. "You can't be yourself on here!" he complained. "People twist things so that is it ... 100% that's it!" Six hours later, he was coaxed back by fans. Accused of attention-seeking, he replied: "If I want [attention], I'll just go to the Trafford centre in my Lambo[rghini]!"

Savage was not October's most high-profile Twitter departee, however: that dubious honour must instead go to Stephen Fry. When Attitude magazine quoted Fry as suggesting "humorously" that straight women only go to bed with men "because sex is the price they are willing to pay for a relationship", it was re-reported by newspapers, angering feminists and prompting Fry – not for the first time – to leave Twitter using his signature valedictory, "Bye bye". He returned days later to explain himself.

If Fry made a dramatic exit, then Twitter's biggest entrance was probably that of Kanye West, who was taken by the site's charms in July, and proceeded to monopolise the feeds of all who followed him. In September he used Twitter not to incite a controversy, but to defuse one, with a 100-plus series of tweets making up a lengthy apology to Taylor Swift for having interrupted her acceptance speech at the 2009 MTV Awards ceremony.

Even less capable of shame than West is his fellow social networker Sarah Palin, TV star and sometime vice-presidential candidate, who in July used Twitter to invent the word "refudiate", as in "Peaceful New Yorkers, pls refudiate the Ground Zero mosque plan if you believe catastrophic pain caused @ Twin Towers site is too raw, too real". Informed by her many detractors of the mistake, Palin naturally compared herself to – who else? – Shakespeare. "'Refudiate', 'misunderestimate', 'wee-wee'd up'. English is a living language. Shakespeare liked to coin new words too. Got to celebrate it!"

Political tweeting caused trouble this side of the Atlantic, too. Kerry McCarthy, the Labour MP who was the last government's "Twitter Tsar" made the elementary mistake of tweeting the favourable results from a sample of early postal votes in her Bristol East constituency, days before the May general election. McCarthy retained her seat, but was given a police caution.

In November, Gareth Compton, a Conservative councillor from Birmingham, was arrested after making an "ill-advised attempt at humour" by tweeting the suggestion that Independent columnist Yasmin Alibhai-Brown be stoned to death. He should have known better: in the same week, 27-year-old accountant Paul Chambers lost an appeal against his conviction for his own misguided Twitter joke: "Crap! Robin Hood airport is closed. You've got a week and a bit to get your shit together otherwise I'm blowing the airport sky high!!"

The otherwise tech-savvy Tory election team also saw their clever use of social networking backfire in March, when they invented the "CashGordon" hashtag as part of their web strategy, setting up a site devoted to exposing Labour and Gordon Brown's financial links to the troublesome Unite union. All tweets appended with the tag #cashgordon would appear on the site's front page. The ruse, however, was quickly uncovered by skeptics – who hijacked the campaign with anti-Tory tweets instead.

OMG! The year's scandalous tweets...

@pauljchambers Crap! Robin Hood airport is closed. You've got a week to get your shit together, otherwise I'm blowing the airport sky high! (6 January. The tweet led to Chambers' arrest)

@SarahPalinUSA Peaceful New Yorkers, pls refudiate the Ground Zero mosque plan if you believe catastrophic pain caused @ Twin Towers site is too raw, too real (18 July. Fanning flames of controversy)

@GarethFCompton Can someone please stone Yasmin Alibhai-Brown to death? I shan't tell Amnesty if you don't. It would be a blessing, really. (11 November. Conservative councillor attack on the Independent columnist)

@TheFagCasanova If you add #mademesmile to your tweets, they appear on a live stream on Vodafone's website, now don't you go abusing them about tax dodging (12 December. Triggered a Twitter protest)

@ElizabethHurley @warne888 Oooooh, I love scary rides - remember to scream if u want to go faster! (11 December. The married model-turned-farmer Liz Hurley's flirtation with Australian cricketer Shane Warne)

@kevinpp24 Yep. Done for rest of summer!! Man of the World Cup T20 and dropped from the T20 side too. Its a f**k up!! (31 August. Cricketer Kevin Pietersen reacts well after failing to make the England squad)

@wossy Good morning. My day is turning out to be far more interesting then I had anticipated! See you later – have a good one. (7 January. Jonathan Ross tweets just before the announcement that he was leaving the BBC)

@StephenFry So some paper misquotes a humorous interview I gave, which itself misquoted me and now I'm the Antichrist. I give up (2 November. Fry gives up Twitter, briefly, after claiming women don't enjoy sex)