Holidaymakers in Dubai this summer should be careful what messages they send home after a new law means anyone caught swearing over WhatsApp could face a £45,000 fine.
Using foul language in texts could also carry a prison sentence while foreigners could face deportation under the new legislation.
The strict new rules came to light after the UAE's Federal Supreme Court ordered the re-trial of a man who was ordered to pay £523 when he was convicted of swearing at a colleague over the messaging app.
Prosecutors appealed the fine claiming it was too lenient and the man should be fined up to £43,569 or face jail.
The exact words used were not revealed but were said to be 'insulting' by the court.
The defendant was prosecuted under the Cyber Crimes Law which makes online verbal insult a criminal offence.
He he was cleared of further claims that he had threatened to harm the claimant
Use of the forthcoming middle finger emoji - an illegal gesture in the UAE - may carry up to three years in jail or a £87,000 fine according to legal experts.
Criminal defence lawyer Abdullah Yousef Al Nasir told 7Days: 'Sending a middle finger emoji on a smartphone or even sending a middle finger picture through email can put you in trouble.
'With the development of technology, people have started insulting others on social media using services like WhatsApp or BlackBerry messenger,' he added.
'Some people insult or mock others thinking nobody can prosecute them. But the UAE has issued a cyber-crimes law to punish anyone committing any crime like insulting someone using technology.'
The case has now been referred to the Court of Appeal, and a date for the new trial has yet to be confirmed.
The Emirates' biggest and most cosmopolitan city, Dubai, has the most relaxed social codes in the conservative Gulf region.
But foreigners occasionally run afoul of strict decency laws and prohibitions on public intoxication.
British citizens have received jail sentences here after being found guilty of kissing in public and having drunken sex on the beach.
Other foreigners have been prosecuted for exchanging steamy text messages or showing a middle finger to a fellow driver.
Last Christmas the British Embassy launched a campaign to warn Britons heading to Dubai or Abu Dhabi for winter sunshine to avoid holding hands, kissing or being drunk on the street.
Embassy staff in the United Arab Emirates created a play on the Twas the Night Before Christmas poem, which included travel advice to help keep Britons out of trouble.
The rhyme - meant for visitors to the Emirates, an oil-rich seven-state federation of former British protectorates - highlights potential cultural pitfalls through the eyes of fictional traveller Stu Nichola
‘No holding of hands or Christmas kisses; under the mistletoe, despite amorous wishes,’ goes a festive nugget.
Another says: ‘So time to go home after several spirits neat; but it's a crime for Stu to be drunk on the street.’
Millions of foreign tourists each year are drawn to the Emirates by beaches with nearly year-round sunshine and attractions such as the Burj Khalifa, the world's tallest building.
More than 100,000 British citizens live in the Emirates, and about a million visit the country each year, according to the embassies in Abu Dhabi and Dubai.