Just a week ago, a group of residents of Poble Nou, a trendy neighborhood in Barcelona because of its proximity to the beach and for being home to various technology companies, called a popular assembly on the street to protest a rise in rent prices. Taking advantage of the good weather, the neighbors - mostly young people, but also older people and some foreign residents - sat under the shade of the trees, facing a giant banner that read: "Has your monthly rent risen so much that you are forced to leave your apartment? Join us in the Assembly of Neighbors to discuss the problem of the price of housing."

Poble Nou is not the only neighborhood facing a lofty rise in rent prices in Barcelona over the last three years. In some neighborhoods, prices have risen as much as 27 percent. The Gothic Quarter, El Born, El Raval and other neighborhoods in the city center have become almost inaccessible to residents of the city. The reason? According to some citizen platforms, Airbnb and temporary vacation rental services are responsible, as they allow flat owners to multiply their incomes if they decide to rent their apartment on Airbnb instead of making a "traditional" long-term rental contract to a local. A two-bedroom apartment in Poble Nou, for example, could be rented a few years ago for about $900 a month. Now the rent can be as high as $1,600 or $1,800.

Obviously, this is not about demonizing Airbnb. The main reasons for the rental boom point more to financial variables, a positive economic environment, or the impact of real estate speculation. But the effort to regulate the market of holiday rental homes has become a prime objective for the Mayor's Office of Barcelona, as the situation not only threatens to drive residents out of the center of the city but also because it causes local unrest: people complain about the presence of tourists in their buildings, noise, parties until late at night, insecurity, loss of control of who gets in and out of a building... The list goes on.

So the Mayor's Office of Barcelona, pushed by the hotel lobby, has been involved in a tough (and effective) campaign for two years to restrict platforms like Airbnb, which has had no choice but to collaborate in order not to lose its reputation in such a popular travel destination like Barcelona.

One of the first regulations applied by Barcelona in collaboration with Airbnb was to require all those who want to offer their house or a room through Airbnb to have a tourist license, for which an annual fee must be paid. Barcelona has not granted tourist licenses for years, so the number of holiday apartments is limited, although there are still plenty of illegal offerings on the internet. Airbnb collaborates with the City Hall in this regard and has been eliminating all advertisers without a tourist license, who can be reprimanded with fines of more than $6,000.

Since June 1, the measures are even more restrictive. Airbnb has launched a new tool on its website to restrict illegal flats and will ask advertisers for consent so that certain data, including their name, address and ID, can be shared with the Barcelona City Council as well as other local and regional authorities.

With this initiative, Airbnb seeks to "verify in an easier way that accommodations comply with the law and help eliminate potential bad actors."

The platform has confirmed that more than 2,500 advertisements of tourist flats have been removed since the municipality began to identify users who did not meet local standards.

"Taken together, these measures have global significance for cities managing their own fights against out-of-control vacation rentals. Firstly, they provide a ready-to-go model that makes enforcing local rules not just feasible, but relatively easy. Secondly, they show that concerted pressure from local governments can indeed push Airbnb and other home-sharing sites to take real action," as reported in City Lab.

Barcelona’s successes with enforcement can set an example for other European cities trying to crack down on an excess of tourist rental flats. After various failed measures, Berlin is now considering introducing a licensing system and heavier maximum fines for rule-breakers. It also seems likely that the German city will seek some kind of data access like Barcelona does.