We got so fed up with being harassed by the kids in train stations (who weren't playing deaf or mute but wanted money and signatures for schools... right... exact same format as the "petition" shown in the photo) that my son, who was getting kinda tired, finally said-

Je n'ai pas de coeur

Loud enough for everyone to hear it. They left. It's probably best not to engage them whatsoever, just keep on walking, but if you're going to engage them, and by the way these urchins spoke nearly-perfect English and would progress from soft pleas to insulting you if you didn't give them money, then you might as well throw them something they can't deal with. Which he did.

Regarding theft, I had my iPhone pick-pocketed on an overstuffed tram in Grenoble July 23rd. The police could care less, and realistically, what could they do? It was so obvious what happened, looking back on it. There was a woman with a baby stroller, but no baby in it. In all her jostling bumping & grinding to get out, there were many opportunities for her and/or an accomplice to pickpocket to their heart's content. First time that's ever happened to me, in 11 trips to France. Haven't felt that stupid in a very long time.