Hundreds of thousands of empty homes across Madrid have spawned a black market in cheap lodging. Criminals break into flats and then rent out the properties.
Most of the cases involving the properties, generally owned by Spanish banks, are identical, says Vicente Perez of residents group the Federacion Regional de Asociaciones de Vecinos de Madrid. "Somebody goes and kicks in the door. Once he's in, the others come and they sell the place," he adds.
It costs from €1,000 (HK$10,700) to €2,000 to "buy" a stolen property, El Pais reports. Those who cannot afford the fee can choose to rent for a few hundred euros a month.
The price often includes electricity, gas and water, and sometimes heating. The living situation lasts until a judicial process issues an eviction order, says Perez. That process that can take up to two years. Figures on how many people are taking part in such arrangements are hard to come by, he says. "People are scared and they don't want to talk."
Nearly 15,000 households in Madrid received eviction notices in 2012. Coupled with sky-high unemployment rates, the evictions have triggered "infinitely long" waiting times for subsidised housing, Perez says.
"A few shameless people are taking advantage of the needs of the most poor to make a business out of it," he says.
The landlords of this black market range from people looking to make money to criminal groups. "Some of them are mafia," says Perez. "They are highly organised."
Spain's Guardia Civil police force acknowledged the problem last month when it responded to neighbours' complaints about an illegally occupied flat. Police found a prospective tenant being shown around the foreclosed flat.
Two siblings, aged 33 and 28, were arrested for breaking and entering into foreclosed properties and illegally renting them out. The duo targeted immigrants, who were charged €400 a month for flats.
Manuel San Pastor, a lawyer for Plataforma de Afectados por la Hipoteca, says the root of the problem was Spain's "hundreds of thousands of empty properties". His group provides support to Spaniards facing eviction, including negotiating with banks.
Ten years ago Spain was in the throes of a construction boom, with developers building hundreds of thousands of homes a year. The bubble burst in 2007, leaving its relics scattered across the country, including more than 300,000 empty homes in Madrid.
In 2013, in an effort to convey the size of Spain's construction bubble, a group of civil engineers and an architect created Nacion Rotonda, or Roundabout Nation. Their aerial pictures show dozens of Spanish neighbourhoods, before and after the boom.
Where forests and farmland existed 10 years ago, there are now half-built homes, roundabouts and roads leading nowhere.
"It's mind-blowing," says Rafael Trapiello, co-founder of Nacion Rotonda. "These were developments that were thrown together with little consideration for social needs, just big expectations of making money.
"What we've ended up with are ghost towns. There's not much to compare it to across Europe. It's pretty shocking to see," he says.
While he was critical of the people profiting from the dire situation, San Pastor says some people have no choice but to live illegally. "They're still evicting people from their houses," he says. "They're leaving no other alternative but for people in need to enter these houses."
Neighbourhood associations in Madrid have urged owners of empty properties to rent their vacant units.
Census data indicates 3.4 million houses sit empty in Spain alongside another nearly half a million properties that were abandoned part way through construction.