Pop legend Robbie Williams unleashed a true avalanche of comments on Twitter after sticking up his middle finger while performing a song at the FIFA World Cup opening ceremony in Russia. Twitter users were left puzzled as to why.

Thousands of fans in the Moscow's Luzhniki Stadium sang in unison on Thursday with one of the UK's most popular artists. Williams, 44, performed some of his greatest hits in a performance streamed online with millions watching.

While performing his famous "Rock DJ" song at the packed Luzhniki Stadium in Moscow, the singer approached a camera in a nonchalant manner and popped up his middle finger before waltzing off. The ex-Take That star also changed the song's lyrics. Instead of singing: 'Pimpin' ain't easy, most of them fleece me, every night', he sang: "Pimpin' ain't easy, most of them fleece me, but I did this for free."

READ MORE: Robbie Williams is ‘selling his soul’ to Putin, say usual UK suspects

The star's move has arguably garnered him more fame, but also quite a mixed reaction from the online community. The Twitterati did come up with various ideas on why Williams - branded earlier by Russia-bashers as someone who 'sold his soul' to Vladimir Putin – did what he did.

Some claimed that the pop singer merely launched a PR stunt. According to Google search, interest in the singer jumped massively on June 14.

@robbiewilliams Just wants this kind of publicity. Shock factor. He is a real has been fallen star. Needs a pick me up kind of publicity. He got it? — Edu (@EduElacson) June 14, 2018

Just when I thought football couldn't get any classier, Robbie Williams gave the middle finger to his biggest TV audience. A clever PR ploy as millenials no doubt started googling to see who he was. The rest of us just rolled our eyes in exasperation. — DrivingMissDaisy (@MeesyTheMinxy) June 14, 2018

Others accused the veteran pop star of contempt of the tournament and viewers. "A proper disrespect to all the fans, players and families watching from all over the world. We wait every four years for this moment to begin and you're putting your finger up like an amateur," one person wrote on Instagram.

Shocked and appalled to discover Robbie Williams flipped the bird. A disgusting show of machismo, and cultural ignorance/ Millions tuning in to see a spectacular show. This guy should be shunned and all his lyrics on Take That singles should be replaced by Brian Harvey. — Martin McCullough (@realmartinmcc) June 14, 2018

The comments grew bitter and bitter…

He just pretended to want to shoot a ball but let a kid do it and Robbie Williams was the worst opening act in WC history — clementine ☾ (@sweetchiId) June 15, 2018

You flipped off 6+ billion people dude, what is wrong with you? I’m sure your family & country are so proud ... 🙄🙄🙄 #Loser 👎👎👎 — Dhruv Krishnan (@krishnan_dhruv) June 14, 2018

Why can’t the British behave abroad? #britishabroad#WorldCup2018#WorldCup Russians enjoy dream World Cup opening despite Robbie Williams’ finger https://t.co/Gn6YlaN6c4 — Mel Ashleigh (@drmellie) June 15, 2018

So @robbiewilliams decided to act like an idiot at the opening ceremony #nothingnewthere#growup — Joy Balfe (@Joybalfe) June 15, 2018

Others came up with ideas, implying that the whole stunt was aimed at UK "corrupt elite" and "fake news media."

I don't think this was aimed at the viewers. More likely at the UK #corruptelite & #FakeNewsMedia How dare a British star open the Russian #WorldCup lets hope #RobbieWilliams can avoid being accidented or suicided by #DeepState 😎 — Carl (@cj980088) June 15, 2018

Best response to the critics who said he sold his soul.. 👏 👏 👏 @robbiewilliams .Response to some people who criticized him for taking the gig just for money. Robbie Williams😘 #WorldCupRussia2018#WorldCupRussia#RobbieWilliams Robbie #work#WorldCup2018pic.twitter.com/HS3WZVECO7 — Nishanth (@Nishanth316cold) June 15, 2018

While trying to predict what could be next for Robbie Williams, people on Twitter rolled out theories ranging from him being banned from headlining opening ceremonies to… deportation to cold-ridden Siberia.

Think #RobbieWilliams just flip off at the opening ceremony? Predicting we won't see him headline an opening ceremony again any time soon. #WorldCup — Kattis (@kattism) June 15, 2018

Destination siberia hopefully — db (@Pepeb72) June 15, 2018

Some, however, did not let the stunt spoil their mood and lower their sympathy for the star.

Who cares where it is? It’s the World Cup fgs! He was brilliant. Take it for what it is...a great performance for a great occasion 🤦🏽‍♀️ — Caroline (@CeeCee151) June 14, 2018

Robbie Williams managed to get the whole world shouting about him by only lifting ONE finger. Icon. — x (@markydays) June 14, 2018

In the meantime, the choreographer of the opening ceremony Ilya Averbukh told Russian media that he had no idea why the pop legend showed his middle finger. He alleged that it could be a response to criticism from the British media and politicians who slammed Williams' decision to perform in Moscow.

READ MORE: Party like a Russian: Robbie Williams & Ronaldo to star in World Cup opening ceremony in Moscow

Earlier football-mad Williams described the chance to sing at the World Cup opening ceremony as "a boyhood dream," and invited "football and music fans to party with us in Russia… for an unforgettable show."

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