It's understandable that people would want to bring home a trinket from vacation to help them remember the trip and the good times that went with it. Usually, those items are found in giftshops or in streetcorner kiosks. Recently, though, according to The Telegraph, airport screeners in Rome-area airports have found property like marble street signs, mosaics, or cobblestones -- things which are not for sale to the public -- in tourists' luggage.

Police say that "northern Europeans" have been caught looting the ancient artifacts, and that the thievery is becoming more common. "It's a particularly unusual theft and at the same time it's one that we are finding is on the increase and happening more and more often," said Antonio Del Greco, Rome's police chief. It has happened so often, in fact, that on Sunday, Roman police displayed a collection of artifacts that have been taken by tourists in the first six months of 2012.

Del Greco is willing to suppose that the majority of the thiefts were niether premeditated nor intentional. "Those primarily responsible... simply picked up a loose cobble stone or piece of mosaic they have found while wandering around Rome. They then put it in their luggage and take it home with them as a souvenir of their holiday." He mentions other instances -- such as finding large, marble milestones in tourists' suitcases -– that would seem less likely to be an innocent mistake.

When caught, the perpatraitors are "highly embarrassed," but not arrested. This might be because, as the Huffington Post explains, the items have no monetary value. Still, they are important, and Del Greco said that the people who attempt to steal them are trying to take "part of Rome's culture and heritage."

Umberto Broccoli, superintendent of culture for Rome's city council said, "I can understand the legend and splendour that is Rome but that does not mean bits of it should be stolen. By all means, tourists should take as many pictures as they like, but they should not help themselves to cobblestones or other items even if they appear to be discarded. What these people do by stealing these items is show their ignorance."

Broccoli said that if tourists want a souvenir from their trip to Rome, they'll have to find it in a shop.