Many world leaders have fallen victim to the act of plagiarism and caught. Here are prominent leaders who were embarrassed as a result of plagiarizing other people's works.
President Muhammadu Buhari
Ghana's new President Nana Akufo-Addo has been caught plagiarising the speeches of two former US leaders. But he is not the first, and is unlikely to be the last.
Here are some previous examples of prominent politicians caught copying their speeches:
Ghana's president
In a speech at his presidential inauguration on Saturday, he said: "Though our challenges are fearsome, so are our strengths. Ghanaians have been a restless, questing, hopeful people. And we must bring to our task today the vision and will of those who came before us."
At his 1993 inauguration, ex-US President Bill Clinton said: "Though our challenges are fearsome, so are our strengths. And Americans have ever been a restless, questing, hopeful people. We must bring to our task today the vision and will of those who come before us."
Mr Akufo-Addo also said: "I ask you to be citizens: citizens, not spectators; citizens, not subjects; responsible citizens building your communities and our nation."
Again, this was remarkably similar to what another former US leader George W Bush said in his 2001 inauguration speech:
"I ask you to be citizens: citizens, not spectators; citizens, not subjects; responsible citizens building communities of service and a nation of character."
Fallout: Mr Akufo-Addo's communication director Eugene Arhin apologises, calling it a "complete oversight and never deliberate".
Incoming US first lady
In a speech that brought the US Republican National Convention to its feet in July 2016, Melania Trump said:
"My parents impressed on me the values that you work hard for what you want in life; that your word is your bond and you do what you say and keep your promise; that you treat people with respect."
But the woman she is replacing as first lady, Michelle Obama, said in 2008:
"And Barack and I were raised with so many of the same values: That you work hard for what you want in life; that your word is your bond and you do what you say you're going to do; that you treat people with dignity and respect, even if you don't know them, and even if you don't agree with them."
Mrs Trump's speech continued:
"[My parents] taught me to show the values and morals in my daily life. That is the lesson that I continue to pass along to our son. And we need to pass those lessons on to the many generations to follow, because we want our children in this nation to know that the only limit to your achievements is the strength of your dreams and your willingness to work for them."
Mrs Obama said:
"And Barack Obama and I set out to build lives guided by these values, and pass them on to the next generations. Because we want our children, and all children in this nation, to know that the only limit to the height of your achievement is the reach of your dreams and your willingness to work for them."
Fallout: An employee of the Trump Organization, Meredith McIver, said she offered to resign for "my mistake", but it was rejected.
Nigeria's president
In a speech to launch a "Change begins with me" campaign in September 2016, Muhammadu Buhari said:
"We must resist the temptation to fall back on the same partisanship, pettiness and immaturity that have poisoned our country for so long."
This time it was Barack Obama, whose 2008 words were copied:
"Let us resist the temptation to fall back on the same partisanship and pettiness and immaturity that has poisoned our politics for so long.''
Fallout: Mr Buhari's office blames an "overzealous" staff member, saying he has been relieved of his duties.
UK opposition leader
In a speech at the Labour party's annual conference in 2015, Jeremy Corbyn said:
"Since the dawn of history in virtually every human society there are some people who are given a great deal and many more people who are given little or nothing. Some people have property and power, class and capital, status and clout which are denied to the many."
This sounded familiar to those who had read a 2011 blog by Richard Heller, once an adviser to former Labour deputy leader Denis Healey:
"Since the dawn of history, in virtually every human society there are some people who are given a great deal and many more people who are given little or nothing. Some people have property and power, class and capital, status and even sanctity, which are denied to the multitude."
Fallout: None. Mr Heller denied Mr Corbyn was guilty of plagiarism, saying he had sent quotes to Mr Corbyn's team. He was happy they were used; previous Labour leader Ed Miliband hadn't.
Madagascar's president
At his inauguration in January 2014, Hery Rajaonarimampianina said:
"I asked my friends who have accompanied me to let me be free, free to move towards others, those who were never my friends, who never belonged to our camp, our political family, who sometimes fought us. Because when it comes to Madagascar, there are no more camps."
During his campaign for France's presidency in 2007, Nicholas Sarkozy said:
"I asked my friends who have accompanied me to let me be free, free to move towards others, those who were never my friends, who never belonged to our camp, our political family, who sometimes fought us. Because when it comes to France, there are no more camps."
Fall-out: None. The Malagasy leader's campaign director Jaobarison Randrianarivon responded by saying that "you can take a quote from a person when needed".
Irish prime minister
While introducing Mr Obama to a crowd in Dublin in 2011, Enda Kenny said:
"If there's anyone out there who still doubts that Ireland is a place where all things are possible; who still wonders if the dream of our ancestors is alive in our time; who still questions our capacity to restore ourselves, to reinvent ourselves and to prosper, well today is your answer."
This may have rung a bell with the listening Mr Obama. In 2008, he had said:
"If there is anyone out there who still doubts that America is a place where all things are possible; who still wonders if the dream of our founders is alive in our time; who still questions the power of our democracy, tonight is your answer."
Fallout: None. Mr Kenny's spokesperson denied the plagiarism charge, saying Mr Kenny was just "drawing on a very well-known speech by Barack Obama and just putting it into an Irish context and an Irish setting".
US president
But Mr Obama has also been accused of copying his words. In a 2008 speech, Mr Obama, then a US senator making a bid for the presidency, said:
"Don't tell me words don't matter! 'I have a dream.' Just words. 'We hold these truths to be self-evident, that all men are created equal.' Just words. 'We have nothing to fear but fear itself.' Just words, just speeches."
He was accused of plagiarising a 2006 speech by former Massachusetts Governor Deval Patrick:
"We hold these truths to be self-evident, that all men are created equal'- just words. Just words. 'We have nothing to fear but fear itself''- just words. 'Ask not what your country can do for you, ask what you can do for your country' - just words. 'I have a dream' - just words."
Fallout: Mr Obama said Mr Patrick had suggested "we use these lines", and admitted erring by not crediting him.
Former Canadian prime minister
Calling for the deployment of troops to Iraq in 2003, Stephen Harper, then leader of the opposition Conservative Alliance who became Canada's prime minister three years later, said:
"As the possession of weapons of mass destruction spreads, the danger of such weapons coming into the hands of terrorist groups will multiply, particularly given in this case the shameless association of Iraq with rogue non-state organisations. That is the ultimate nightmare which the world must take decisive and effective steps to prevent. Possession of chemical, biological or nuclear weapons by terrorists would constitute a direct, undeniable and lethal threat to the world, including to Canada and its people."
Several days earlier Australia's then-Prime Minister John Howard had said:
"As the possession of weapons of mass destruction spreads, so the danger of such weapons coming into the hands of terrorist groups will multiply. That is the ultimate nightmare which the world must take decisive and effective steps to prevent. Possession of chemical, biological or nuclear weapons by terrorists would constitute a direct, undeniable and lethal threat to Australia and its people."
Fallout: Five years later Mr Harper's speechwriter Owen Lippert was forced to resign from the Conservative campaign headquarters after the rival Liberal Party used the speech to embarrass its head of elections.
US vice-president
Campaigning to be a presidential candidate in 1987, then-Senator Joe Biden said:
"Why is it that my wife who is sitting out there in the audience is the first in her family to ever go to college? Is it because our fathers and mothers were not bright?"
He was accused of plagiarising from a 1986 election campaign commercial by then-UK Labour leader Neil Kinnock:
Why is Glenys [Mr Kinnock's wife] the first woman in her family in a thousand generations to be able to get to university? Was it because all our predecessors were thick?''
Mr Biden also said:
''Those same people who read poetry and wrote poetry and taught me how to sing verse... Is it because they didn't work hard? My ancestors, who worked in the coal mines of north-east Pennsylvania and would come up after 12 hours and play football for four hours.''
Mr Kinnock said:
"Those people who could sing and play and recite and write poetry? Those people who could make wonderful beautiful things with their hands? Those people who could dream dreams, see visions? Why didn't they get it? Was it because they were weak? Those people who could work eight hours underground and then come up and play football? Weak?"
Fallout: The truth was that Mr Biden's ancestors were not coalminers, his Democratic rival Michael Dukakis made political capital out of the plagiarism row, and it was widely seen as having destroyed his presidential ambitions.