As we glide under a bridge on the Copenhagen canal tour, our guide announces that we have entered a quiet zone. "This is a residential area," she says, nodding towards balconies where Danes are enjoying coffee - or maybe wine. "I'll resume talking in five minutes." Denmark is one of the world's top destinations for conferences and a mainstay of transatlantic cruise ships. Attracted by noir detective series and fashionable cuisine, nine million tourists visited the city last year, a record for Denmark, which has fewer than six million people.

The "quiet zones" are emblematic of the Danish philosophy towards tourists:

They should blend in with the Danish way of life, not the other way around. The Danes have prohibited foreigners from buying vacation cottages on their sea coasts; devised their famous bicycle-friendly transportation system to include tourists; and strictly limited bars and restaurants from taking over Copenhagen.

The question, says Mr Henrik Thierlein, a spokesman for the city's tourism office, is: "How do you take advantage of the growth in tourism and not be taken over by mass tourism?" Outraged by tourists' boorish and disrespectful behaviour, and responding to the complaints of their constituents, local officials around the world have begun to crack down on tourism, and the industry, even in the face of opposition from their national governments, which want the tax revenue from tourists.

Barcelona, a city of 1.6 million that draws more than seven million people a year, represents the turn towards regulation. Taxis and tour buses have taken over entire neighbourhoods, while souvenir shops and bars have displaced pharmacies and greengrocers.

Mayor Ada Colau, 41, who was elected in May, has announced a one-year ban on new tourist accommodation, citing the swarms of students who have all but taken over the Ciutat Vella, or Old City, of Barcelona. In August last year, hundreds of residents erupted in spontaneous protest after images of three Italian tourists wandering naked in the neighbourhood of La Barceloneta were circulated online. Her greatest worry, Ms Colau says, is Barcelona's turning into Venice.

In Asia, alarm has centred on Chinese tourists; there are more of them than from any other nation. China began loosening severe travel restrictions only about 25 years ago, and the rapid rise of the country's middle class has sent curious - but often naive, rude or even destructive - visitors throughout South-east Asia.

In Thailand, a Chinese tourist was recently caught on video ringing and kicking sacred bells at a Buddhist temple as if he was in a game arcade.

There have been reports of Chinese tourists littering beaches and even defecating in public. One tourist even opened the door of an airplane, as it prepared for takeoff, reportedly to get fresh air. The Chinese government responded by promising to set up a tourist black list to ban notorious known offenders from travelling overseas for up to two years.

Of course, the Chinese aren't the only culprits. In Cambodia, half a dozen foreigners, including three Frenchmen and two American sisters, were deported in February for posing nude in Angkor Wat. I was in Cambodia when the scandal broke, leading a discussion near the temples about protecting cultural sites visited by tourists. The authorities are now considering a code of conduct that would ban not only nudity but also the touching of ruins.

Bhutan, wary of uncontrolled tourism, is going further - it has restricted the number of tourism visas, curbed hotel construction and imposed a high tariff on tourism, all part of a strategy of "low-volume and high-value tourism". Such battles have even reached the tourism-friendly US.

A decade after Hurricane Katrina ravaged New Orleans, city officials have eyed tourism as the best path towards a revival. But homeowners in the French Quarter say the city fails to properly enforce zoning and noise regulations, inviting the party crowd into their streets. Last year, residents of Charleston unsuccessfully sued to block the South Carolina port authority from opening the port to more and larger cruise ships.

Tensions are bound to get worse. Notwithstanding worry about carbon emissions, more of the world's peoples are crossing borders for leisure than ever before. Tourism now accounts for one in 11 jobs worldwide.

In 2012, the global tourism industry counted a record one billion trips abroad, and many more tourists travel within their home countries. Travel contributes US$7.6 trillion (S$10.4 trillion) to the global economy, nearly half the entire economic output of the United States.

One reason tourism is hard to regulate is its positive associations, not only with pastime and leisure but also with cultural prestige. People are proud of the vistas, landmarks and monuments that their homelands are best known for. So efforts to regulate tourism aren't always popular.

France is an exception, which is remarkable given that it is also the most-visited country in the world. In the 1950s, with US aid from the Marshall Plan, the French government used tourism to help rebuild the country. It discovered that tourism, when done properly, could underwrite the protection and nurturing of France's culture, landscape and way of life.

In practical terms, that means tourism is not only promoted and subsidised but also regulated, at all levels of government, in all matters of policy.

Tourism is considered, for example, in plans for preserving and protecting the countryside, the vineyards, forests, small villages and farms, the coastline, the bicycling routes and the ski slopes. (France is the world's top skiing destination.) French officials debate whether Bordeaux needs another five-star hotel; which ski resort in the French Alps needs another lift; whether Provence needs more vacation rental homes.

The rules are enforced with impartiality. The special favours and corruption that mar tourism in other countries are mostly absent in France.

Patrimony and tourism feed each other. France invented the first ministry of culture and then spread festivals around the country to send visitors far from Paris: music in Aix-en-Provence, film and advertising in Cannes; photography in Perpignan and dance in Montpelier.

Bordeaux undertook a mammoth 15-year restoration of its 18th-century historic centre - a project as complicated as Boston's Big Dig - with tourism in mind, as Mr Alain Juppe, the mayor (and a former prime minister of France), told me.

Like Copenhagen, Paris uses noise and zoning laws to keep tourism from getting out of control. And it handles the flow of tourists with the seriousness of a military operation.

The Eiffel Tower, with seven million visitors each year, is the world's most heavily visited paid attraction. Tickets are limited and timed to the half-hour. Visitors move up and down under the watch of discreet guards. The gardens surrounding the tower are kept manicured by a full-time crew of 38 workers. Loitering is forbidden; street vendors are strictly regulated. Similar restrictions apply at other tourist spots, like the gardens of Claude Monet in nearby Giverny. Paris is, first of all, for Parisians.

That was illustrated last month in a rare standoff between tourists and locals. For several years, tourists had disfigured the Pont des Arts by hanging padlocks on the pedestrian span as a sign of love. Parisians despised these "love locks". After several compromises failed, the city government removed them.

The UN World Tourism Organisation projects that by 2030, global tourism will reach 1.8 billion trips a year. It is now so big that it will inevitably be part of conversations about climate change, pollution and migration. Without serious government attention, many beloved places will be at risk of being trammelled and damaged - what those in the tourism industry call being loved to death.

NEW YORK TIMES