It's just a very sad, sad situation in general.
When I first came here, I was a definite soft touch when I saw people of all ages begging, I mean, it got to me, especially because there are indeed some people who really don't have a means of supporting themselves.
In the beginning, I gave up quite a bit of change/$2 peso bills, but that got phased out pretty quickly. When I did give up a single moneda to any beggar, even without saying a word revealing an accent, the next thing you know, I had just pretty much invited a slew of other people to start demanding what they felt they had coming. Not surprisingly, each new person got a little bigger and more intimidating. And it's gotten so bad that even on the subway, when I used to feel okay just giving a little kid an alfajor or something small to eat, it normally wound up putting me in a potentially dangerous predicament, especially because you can't just flee from the confrontation when you're in the subway car.
It hasn't even been limited to just giving change on the street. One day there was a person outside our building, pressing all the buzzers and asking if we had any clothes to donate. By chance, I did have a few random things I was going to get rid of anyway, so I thought, "why not?" BIG mistake.
I was a little surprised (and admittingly naive at the time) when the bag of clothes was just snatched out of my hand and not even a "gracias." I had forgotten about it... Until the next thing you know, the buzzer kept ringing. And ringing. And ringing. I'm sure that we all know why.
My Argentine husband is a very decent and generous guy, but he knows here it can get very dangerous, very fast, especially for a woman who only means well. He's a calm guy, and it's extremely rare that he ever "puts his foot down" with me, but he has told me (as in, non-negotiable, DO NOT, because I forbid it) that I was NEVER to "donate" clothes like that again, especially because one sudden push when I have the building door open just a few inches and we're all in serious danger. Like I said, very naive on my part, but well-meaning.
One of the worst incidences for me was a couple of months ago. I was only in my first trimester or so, not showing any visible signs of a pregnancy, but I went to a take out place a few blocks from my house to buy a box of empanadas to go. Shortly after I left, I started getting seriously heckled (thankfully it was only verbally) by a pregnant woman who had a toddler in tow because I wouldn't stop to give her the food. Now more than ever, I mean, that really gets to me. But after awhile, I just feel fed up and a part of me wants to say, "No, I won't give you my empanadas that I bought with my own money because you won't LEARN anything!" But of course, I don't.
Agreed with prior comments... It's not even an acute "to give or not to give a coin" issue... This issue needs some serious consideration and investment (how/from whom, I can't say, but it can't always boil down to a person-to-person confrontation every single day!).