The problem with this thread is that it is based on the assumption that swarms of kids can do what they want because they have no fear of being arrested. And it's wrong.
Unfortunately (for them) they can be arrested. Unfortunately (for us) they can't be sentenced to prison and flee the protected houses after a couple of days. But they are absolutely afraid of being arrested because they'd loose a day of work and they are beaten by their owners when they don't bring "home" any money.
Taking them away from the families who send them to pickpocket doesn't work. These groups are not made by locals, when the social services get too close, they just move the kids to another EU country with new names and new owners. Or they all go back to eastern Europe for a while to get new IDs.
Same for pregnant minors, who are those who actually pickpocket most tourists: they can't be sentenced to prison unless there is space in the few prisons with maternity rows and they can't be expelled to Bosnia because it's not a country and it's not safe. But they can be arrested, prosecuted... and spend 22 years in prison when they grow up. (True story)
So what's left of the above advices? Dunno, but...
- Be aware of who's getting too close, do not trust any young girl who is also pregnant. They have no honest reason to come close to you.
- No European knows what a money belt is, but If it makes you feel safer get one.
- The last group of pickpockets arrested in Rome was made of Peru nationals older than 18 and posing as tourists: do not make assumptions based on age and race.
- In any case, do NOT touch kids and do NOT threat them. You can be arrested, fined and prosecuted and these groups have lawyers.
To give you an idea: some of those underage Bosnian pregnant girls have learnt to report cops for sexual abuse.