TORONTO - About 290,000 people follow Prime Minister Stephen Harper on Twitter, perhaps to read what he has to say about the country's affairs or to glean a little personal insight into what makes him tick.

Thing is, most of the messages that are sent from his account aren't really his.

Harper only "occasionally" sends out tweets himself, according to a spokesman.

Much like many other high-profile Twitter users, most of the short-form messages that appear under Harper's name and avatar are actually crafted by ghost-tweeters charged to work social media on his behalf.

"I assume if it's an institutional individual — if it's a CEO, if it's a big personality, a singer, or it's a politician — then they are not doing it themselves," said Greg Elmer, director of the Infoscape Research Lab at Ryerson University studying social media.

"It's another example of public relations, it's professionally managed communications."

It's tough to know whose tweets to trust. Sure, there's Twitter's official verified stamp of approval, letting users know the account isn't run by an imposter, but that doesn't confirm who actually writes the tweets.

"You don't really know if it's really that person and their voice and their actual words," said social media consultant Andrew Escobar, who suggested even experts can be fooled by a good ghost-tweeter.

"Obviously with some tweets you can sort of gauge if it's a staffer writing it in a very formal way and it's not their words, but you never really know. At the end of the day it might be someone tweeting on their behalf — you have to use your judgment."

In November, media outlets gleefully reported that "Harper took to Twitter" and came to Justin Bieber's defence after the pop star was heckled online for wearing casual duds to receive a Diamond Jubilee medal.

Harper's account had tweeted a photo of the pop star showing up to a photo-op underdressed in a T-shirt, overalls and a backwards-turned ball cap. After the picture went wild on social media, "Harper" tweeted: "In fairness to Justin Bieber, I told him I would be wearing my overalls too," which was retweeted nearly 10,000 times and marked as a favourite by more than 4,100 users.

A spokesman for Harper would not say whether it was the prime minister who penned that tweet.

Elmer said reporters and editors should take a harder line on confirming who actually wrote a tweet if they plan to attribute words to someone.

"I would say that it's sloppy to convey to Canadians, to readers, that the prime minister is sitting in the back of his car, on the way to the Hill, with his thumbs on his BlackBerry or iPhone," Elmer said.

"I think it's important for Canadians to realize that the Prime Minister's Office is a very sophisticated communications outfit and a big part of that in today's economy and today's world is managing and monitoring social media."

Elmer said it was a savvy move on the part of Harper's communications team to win some points with Bieber's young fans.

"What his communications staff is trying to do in that instance is to use an opportunity where they felt that a lot of young voters, young Canadians, would be paying attention to this on social media and they used that opportunity to serve up a quote-unquote 'personal tweet' from the prime minister," he says.

"This is a prime minister who's done very well in surprising Canadians with his different public faces, as someone who's very much interested in hockey, as a cat lover, as a musician onstage ... he's shown a history of taking advantage and positioning himself within the particular events that are happening at any given time."

Escobar was among those who were taken aback by the tweet, but thought it was good social media strategy. At first read, Escobar actually assumed it was sent out by a parody tweeter and not Harper's real account.

He figured Harper wasn't actually tweeting himself. And he isn't sure what to think about Bieber's massively popular account, which has 33 million followers and regularly interacts with fans.

"I think my guess with Justin Bieber would be that it's someone tweeting with him," Escobar said, adding that if the young star was tweeting himself, he would probably have gotten in some trouble by now.

"I don't really think he makes many mistakes on Twitter but they very much go the extra mile — if it isn't him — to make it look authentic. There isn't much care in the spelling, grammar — excessive use of punctuation, no capitalization — it's very informal in the way an 18-year-old of his fame would tweet."

A spokesman for Bieber did not immediately return a request for comment.

Eric Alper, director of media relations for eOne Music Canada, believes it's actually Bieber at the helm of the account.

"I have absolutely no doubt that's Justin Bieber, that's absolutely him," said Alper, who added that he's written some tweets for some artists in the past.

"With celebrities you can pretty much figure out who's tweeting on behalf of the artist or celebrity and who's not. If their whole Twitter feed is written very, very carefully, short, sweet and probably promotes something, it's going to be a handler, whether it's a manager or an assistant or somebody from the record label taking it over."

It's also a safe bet that stars are tweeting themselves when they get into trouble for their online comments. Courtney Love paid US$430,000 to settle a defamation suit over tweets she wrote about a fashion designer. And Chris Brown deleted his Twitter account (it's since been resurrected) after getting into a nasty, expletive-ridden spat with a woman online.

If there's one Canadian celebrity's Twitter account that seems easy to peg as authentic it's Don Cherry's. The oft-controversial CBC personality made headlines recently for questioning whether Canada should be spending tens of millions on aid for Haiti.

Cherry doesn't physically type in each tweet but they are his words and opinions, said CBC spokesman Chuck Thompson, adding the tweets are sent out by longtime "Hockey Night in Canada" producer Kathy Broderick.

"Those are definitely his words that he relays to her, so she tweets on his behalf," Thompson said.

Fans love the connection they have with their favourite stars through Twitter, but some artists' managers believe social media can be a liability, Alper said.

"There are some cases where I'm sure there's a lot of nervous nights from publicists, record labels and marketing people when their artists decide not to have a buffer and tweet away," he said.

"For the most part people know now, maybe they didn't before, but they certainly do now that you're not just tweeting out to your audience, all it takes is for one person to retweet it and it goes beyond."

Related on HuffPost:

Loading Slideshow...
  • Best MPs On Twitter

    Here's our totally unscientific look at which Canadian politicians are making the best use of Twitter. (CP)

  • 14. Rona Ambrose

    Tory ministers dominated our <a href="" target="_hplink">worst MPs on Twitter list</a>, but <a href="!/MinRonaAmbrose" target="_hplink">Rona Ambrose</a> is an exception to the rule. While she could stand to pick up a few more followers, Ambrose is on the right track, heavily peppering her feed with retweets. She also responds to journalists, a sure sign of a strong political account. (CP)

  • 13. Marc Garneau

    Besides tweeting at a furious pace, former astronaut and current Liberal MP <a href="!/MarcGarneau" target="_hplink">Marc Garneau</a> can be seen regularly carrying on conversations with other users. Nothing warms our hearts more than to see one of our politicians engaging with Canadians. (CP)

  • 12. Peter Julian

    NDP MP <a href="!/mpjulian" target="_hplink">Peter Julian</a> is active, interesting and engaged. Good number of photos as well. (CP)

  • 11. Denis Coderre

    With nearly 60,000 followers, <a href="!/DenisCoderre" target="_hplink">Denis Coderre</a> is one of the most popular Canadian MPs on Twitter. He responds to users, retweets news and generally keeps things lively and diverse. And although most of his tweets are in French, he's not afraid of an English post from time to time. (CP)

  • 10. Carolyn Bennett

    Liberal MP <a href="!/Carolyn_Bennett" target="_hplink">Carolyn Bennett</a> has more than 7,000 tweets, a sure sign of a Twitter addict. She also has been known to <a href="!/Carolyn_Bennett/media/slideshow?" target="_hplink">tweets photos of her dinner</a>, a sure sign she stays connected at all times. (CP)

  • 9. Olivia Chow

    With more than 17,000 followers, Olivia Chow doesn't need our help. But we love her tweets, especially the funny ones. This <a href="!/oliviachow/status/198021722232979457" target="_hplink">Rob Ford zinger stands out</a>: "Dear journalists, the lilac tree in front of my #Toronto house is in bloom, come and take a photo by the fence, I won't call 911." (CP)

  • 8. James Moore

    Another Tory minister who bucks his party's Twitter trend is <a href="!/JamesMoore_org" target="_hplink">James Moore</a>. His account shows all the usual signs of engagement, but to be perfectly honest it was the <a href="!/JamesMoore_org/media/grid" target="_hplink">cute photos</a> of his <a href="!/JamesMoore_org/media/slideshow?" target="_hplink">two dogs</a> that secured his spot on the list. (CP)

  • 7. Megan Leslie

    NDP MP <a href="!/meganlesliemp" target="_hplink">Megan Leslie</a> has one of the most active accounts in Parliament. Our favourite tweet in recent months? "Finally found a parking spot in Whitehorse. No need to call Bev Oda's driver." (CP)

  • 6. Peggy Nash

    Unlike <a href="" target="_hplink">Thomas Mulcair, who has stopped tweeting</a> since the end of the NDP leadership contest, <a href="!/PeggyNashNDP" target="_hplink">Peggy Nash</a> continues to post up a storm. Her appearance on this list also has a lot to do with her <a href="!/PeggyNashNDP/status/197057876865454081" target="_hplink">recent allusion to the cartoon "South Park."</a> (CP)

  • 5. Justin Trudeau

    What can you say about <a href="!/JUSTINPJTRUDEAU" target="_hplink">Justin Trudeau</a>? He's the rock star of Canadian politics and his Twitter stats show it. More than 130,000 followers and a verified check mark -- the surest sign of an online celeb. And while <a href="" target="_hplink">HuffPost got into a minor tiff with Trudeau over a tweet</a> he sent out earlier this year about his BlackBerry, we're still big fans of the Liberal MP's stream. What other Canadian politician would have the guts to tweet a photo like <a href="" target="_hplink">this</a>. (CP)

  • 4. Jason Kenney

    <a href="!/kenneyjason" target="_hplink">Jason Kenney's Twitter stream</a> often resembles a travel journal. The Immigration Minister spends a lot of time travelling the country and it shows in his feed and photos. Something else we've learned from following Kenney? <a href="!/kenneyjason/media/grid" target="_hplink">He loves purple ties</a>. (CP)

  • 3. Tony Clement

    Alright, we know we already put <a href="!/tonyclementcpc" target="_hplink">Tony Clement</a> on our <a href="" target="_hplink">worst MPs on Twitter list</a>, but we do have a love hate relationship with the Tory minister. While his tweets have grown less interesting since <a href="" target="_hplink">Jackass-Gate</a>, Clement is still miles ahead of most MPs when it comes to using social media. No wonder he's been<a href="" target="_hplink"> tasked with leading the Conservatives' Open Government initiative</a> to put more federal info online. (CP)

  • 2. Bob Rae

    'Interim' Liberal Leader Bob Rae may not have captured his party's permanent top job yet, but he definitely hold the attention of his Twitter followers. All 26,000 of them. He gets in on <a href="!/bobraeMP/media/slideshow?" target="_hplink">photo meme action</a> and <a href="" target="_hplink">isn't afraid to use colourful language</a>. <a href="" target="_hplink">Compared to the accounts of fellow leaders Thomas Mulcair and Stephen Harper</a>, an absolute gem. (CP)

  • 1. Elizabeth May

    She may be the leader of the smallest party in Parliament, but <a href="!/elizabethmay" target="_hplink">Elizabeth May</a> punches way above her weight online. The Green Party leader has nearly 40,000 followers, roughly triple the count held by <a href="!/thomasmulcair" target="_hplink">Thomas Mulcair</a>. How did she become such a digital success? One word: engagement. May's stream shows consistent interaction with followers and journalists. The leaders of the larger parties could learn a thing or two from this plucky underdog. (CP)