Pirañas in Lima?

Amigos:

You all know about pirañas (or piranhas, in portugese); they are very agresive small fishes that live in the upper parts of the amazonian rivers and they act collectibly as when a young rat or bird (or whatever living creature) falls down to the water near them; they attack this prey in large numbers, so ferociously, that in a couple of minutes nothing rcognizable is left of it.

But, piranhas in Lima?

Yes, we call "piranhas" to large group of juvenile burglars (almost always they are around 13-17 ages old) that roam some well known places in the suburbs of Lima looking for any unawwere by-passer that looks as if he (or she) carries some valuables on ("valuables" can be even an almost new pair of keds, a wristwatch or some coins on the pockets.); inmediatly, and appearing from nowhere, perhaps a dozen "pirañas" jump over their current "customer" and while some of them just inmobilize him (or her),or knock him (her) down, the others pickpocket him (or her) until nothing of value is left; as soon as they appeard, they now dissapear in near passages, abandoned houses or the like, just as their "cousins" of the amazonian rivers do!

You can get an idea of both type of piranhas from the two next links in YouTube (Warning: the scenes from both videos may hurt some sensitive people):

http://mx.youtube.com/watch?v=fxw1EFcm3vw http://mx.youtube.com/watch?v=qeSjgqmsaGw

JSR