|Lock of love|
It 'a tradition of Italian Popular Culture, is believed to be born few years ago,
in Florence around 2000, cadets from the Army, the local academy, and was repeated by other lovers, both in Florence and Rome, was put into a movie "I want You", with the Italian actor Scamarcio (photo of the movie), a romantic movie, in 2007 and became very popular trend.
I personally know people, that have claimed more than 300 km. to go to Milvio Bridge in Rome, to make this promise of love, something very romantic, typically Italian.
Now, this tradition seems to have come abroad, a good thing, maybe try not to overdo it, as happened in Rome, as you can see in the image below: