Padlocks on the lover's bridge

On our Segway tour yesterday (omg so much fun you would not believe. If you can ski, Segway is just like that. Same slaloming motion. And the boy, who had never ski-ed, picked it up really quickly. Mine played up a bit because I'm so light and when going over rough ground it got confused and kept stopping. Ah well.) we went over this bridge, locally called the Lover's Bridge. Couples come here to canoodle and propose - and it seems when they do, they leave a little padlock with their initials carved into it, locked onto the bridge. Is this something done anywhere else in Italy, or the world?