HE is one of the most powerful and wealthy men on the planet but he can still stroll through the streets of Dublin unnoticed by other pedestrians.
The founder of Facebook, Mark Zuckerberg, discarded the trappings of his enormous wealth at the weekend and took to the pavements to get around like any other tourist in the capital.
But he was followed at all times by a security team who kept a discreet distance behind the young billionaire during his stroll.
The 27-year-old, estimated to be worth just under €9.5bn, was in Dublin for a few days to meet with staff at Facebook's European headquarters and take in some of the sights of the city.
At the end of a week when US President Barack Obama shut down the centre of the city for his speech on College Green, the young entrepreneur barely raised an eyebrow among people around town as he chatted on his iPhone.
Eschewing the security vans he had at his disposal, Zuckerberg left the boutique Dylan hotel off Baggot Street on Saturday afternoon and strolled the short distance to Grafton Street.
He arrived in Dublin on Thursday evening and on Friday he called into staff at Facebook's headquarters on Hanover Quay, near U2's Windmill Lane recording studios, where he signed the office's white drawing board.
"First time in Dublin. May 27, 2011. Good to meet all you folks. Mark," he wrote.
Zuckerberg is understood to have attended a party celebrating the first anniversary of Facebook's operation here on Friday night, which also featured the Irish band Bell X1. Some 200 people are employed in the Dublin offices.
However, the weekend was kept for relaxing, with Zuckerberg looking around the Guinness Storehouse yesterday afternoon, although minus the massive attention that Queen Elizabeth attracted when she had a pint laid in front of her almost two weeks ago.
But while he may have seemed to be just another American tourist checking out the sights of the city, there was a significant security presence around him at all times.
As he strolled towards St Stephen's Green, a bulky American bodyguard floated some 20 feet behind him, while another three were always nearby in a silver van and kept an eye out for anything they deemed out of the ordinary.
Zuckerberg's quiet visit to Dublin is in direct contrast with the high-profile appearance he made last week at the G8 summit in Deauville, France.
It was here where the businessman, wearing a shirt and tie -- in a marked change from his normally relaxed hoodie-and-jeans ensemble -- warned world leaders such as French President Nicolas Sarkozy against trying to regulate the internet.
The shirt and tie were most definitely back off when he arrived in Dublin, as he sported the same green hoodie repeatedly over the weekend.
Zuckerberg is seen as a remarkable figure in the world of internet companies, having started Facebook from his dorm room in Harvard University in the US.
'Forbes' magazine estimates his wealth at €9.42bn and the story of how he started the social-networking site was recently the subject of a successful film, 'The Social Network'.
That other massive networking site -- Twitter -- was full of sightings of 'Zucks' last night, with one person saying they saw him enjoying a pint of Smithwicks in the Village venue on Thursday night.
Facebook itself was short on details of the billionaire's visit when contacted by the Irish Independent.
"Mark went to Ireland to spend time with the employees in the European HQ in Dublin. No further details to share," a statement said.
The social-networking site has grown to a colossal 650 million users around the world and has an estimated worth of more than €80bn.