Their Love is Solid as a Lock

Took a stroll today in one of Helsinki's prettiest outdoor venues - Vanhankaupunginkoski (Old town rapids) and saw few of these "love locks" attached to the bridge fence.

Do they toss the key to the river or how does it go? I've seen these abroad but I'm not really sure how does the thing go :)

Another global trend, the sneakers on a wire.