Now the parts of San Francisco I frequented weren't exactly known for large populations of children, so when I started encountering the kids in Dublin, I wondered if all kids were such punks, or if the kids in Dublin were special. I eventually noticed people were calling them "knackers," and while the Dublin variety seem to be a variant of what's described in Urban Dictionary, that definition comes close enough. Often wearing track suits, usually walking around in groups of 3-5, and generally causing trouble.
What kind of trouble? The initial incidents all involved things being thrown at me , mainly rocks. Two groups of kids would be throwing rocks at each other, but when people would walk past, they would alter their trajectories and start to "miss." "Sorry mister!"
There was one other incident involving the throwing of things, though: I was standing near the edge of temple bar spacing out and looking at a restaurant's menu; I was vaguely aware of a group slightly older boys  arguing with each other off to my right, but suddenly, an open packet of biscuits hit me in the side of the head. I kinda looked at them with a "what the fuck?" Their arguing had stopped and they were looking at me but didn't say anything; I just walked away.
Keep in mind: Temple Bar is an incredibly busy area. If I wanted to give them the benefit of the doubt, perhaps they were arguing over the pack of biscuits and in the ensuing tussle it was knocked from someone's hands -- but see above re "benefit of the doubt."
And with regards to benefit of the doubt, it doesn't help that on my walk to work, I regularly see a group of kids being lectured by a couple of Gardai.
Seeing an 8 year old kid in handcuffs is something I'm not sure I'm ever going to get over.
In some conversations I've had with some locals, I've found out a few things. Apparently "knackers" isn't exactly a polite thing to call them -- they're just unsupervised working class kids with nothing better to do than act out. Fair enough, perhaps: it's not like I'm shouting "damn knackers!" at them from my rocking chair or something, but every time I see them doing something, I kinda can't help but think it.
And then there was tonight's incident, which certainly didn't endear them to me any.
I had just left Dunne's Grocery and turned south onto Great George -- I've been trying to keep my wallet in my front pocket but I hadn't remembered this time and it was in my back pocket, and my bag was still only over one shoulder since I was still getting myself together. I heard some feet running towards me and then "Scuzemescuzemescuzeme," as this damn knacker ran into my back and pressed up against me for several seconds before pushing me into the wall and running on.
I immediately checked my bag and wallet and everything was fine, but still, what the fuck? That stretch of Great George isn't quite Temple Bar, but it's still pretty damn busy.
But then the kid ran towards a guy carrying a guitar and pushed him into the street, almost in front of a bus. The guy looked at the kid, grabbed him with one hand, and pushed him off his feet into a pile of garbage bags on the curb.
It was about at this point that several more kids caught up with the first kid, and a couple of them walked towards the guitar man as the first boy picked himself up; they all approached the guitar man, who gave them another look and then jaywalked across George -- something I wouldn't do at the best of times -- followed by the kids.
One of the kids left on my side of the street asked the other "What's he trying to do, get himself arrested?"
At least some of them have some smarts, I suppose.
 Somewhat deflating my original premise, I did just remember that I had rocks thrown at me a couple of times while riding my bike through Western Addition, but that's a whole different problem.
 Now when I say "slightly older," I'm talking 12-13; most of these incidents involve kids who appear to be in the 8-12 range. Seriously.