They're trying to stop couples from doing this
on the Ponte Vecchio, so the lovers have moved
a bit upstream to the Ponte alla Grazie to keep
the tradition going (you write your names on the
lock and toss the key in the water).
Of course, in the Cinque Terre, on the Via dell'Amore,
they're all for the lucchetti d'amore—and
have set up a special place for them.