They mostly end up shame-faced after realising that not only have their well-publicised antics provoked the ire of Rome residents, they have a hefty fine to boot.
But not Delilah Jay, the latest Ekberg-wannabe to take a dip in the 17th century Baroque fountain.
The Local happened to spot Jay - an author, actress, singer-songwriter, former Page 3 model and London Mayor aspirant – sitting outside a café on one of Rome's classiest streets, Via Babuino, on Thursday night.
Far from being embarrassed, the 54-year-old German told us told us she would probably do it again.
“It was a homage to 'La Dolce Vita',” she said of her decision to jump into the fountain earlier this week.
“I love Rome, I love Fellini and I love Ekberg – I've had so many comments on my Facebook page saying I look very much like her.”
Like Ekberg, Jay has blonde hair. She also donned a fur stole (albeit a fake one) for her Trevi debut. Hollywood sex symbol Ekberg also wore a fur stole for the scene in the 1960 film.
But that's as far as the resemblance goes.
Jay declined to let us take a photo of her, because she wasn't wearing her trademark stole, but did allow us to snap a shot of her bag, which has a photo of her with said stole.
As she sat perched on the edge of the fountain, which was only recently restored to the tune of €2.2 million, on Tuesday morning, Jay said “the water called me to jump in”.
And so she did, all the while blowing kisses to hundreds of tourists, some of whom applauded her.
“I didn't really think about it at all, the water was so inviting,” she added.
“An old Italian lady was laughing, telling me that I'll get a big fine! It was so refreshing.”
But her stunt was short-lived. A police officer soon arrived and told her to get out.
She was handed a €450 fine, which she readily withdrew from the nearest ATM.
“I wasn't taken to the police station, but they showed me the handcuffs,” she laughed.
Spontaneity aside, Jay also had another motive to make a splash in Rome – she's hoping the Eternal City will form the backdrop of a film she's hoping to make out of her book, ‘Mistress – The Italian Way'.
She's also in the Italian capital looking for someone to take the film project on.
Berlin-born Jay, who lives in London but spent a decade in Rome in the 1990s, has had a colourful career.
Apart from writing three other books, in 2014 she became the oldest woman to pose topless in the German tabloid, Bild.
The mother-of-one has also appeared on the British cooking show, Come Dine With Me, and this year tried to run in the election for Mayor of London – as an independent candidate under the slogan ‘Love, Peace and Happiness'.
Delilah Jay during her London election campaign.
She wrote on her website that she wanted to replace Boris Johnson, now the UK's Foreign Secretary, “to keep a strict eye on politicians and their actions”.
But her political ambitions were scuppered after she was allegedly threatened by the family of the man who ‘Mistress – The Italian Way' appears to be based on.
Jay once penned a song for the Eurovision Song Contest and auditioned for the talent show, Britain's Got Talent - reading a piece of literature in front of host, Simon Cowell.
She didn't make it through but enjoyed the adulation from presenters Ant and Dec, who sang Tom Jones' ‘Delilah' as she stepped down from the stage.
Indeed, she has also left many others in Rome wondering ‘Why, why, why Delilah'...