Look, let's not try to pick this turd up by the clean end.
Google Polar Bear Hunting, polarbearing, and read a couple articles on the who, where and why.
It has different names in different cities here in the east but it's the same ol same ol.
They really are that easy to spot, Kleanbore.
I think you are giving them way too much credit on the thinking/planning of this stuff.
Pickpockets, purse snatchers, terrorists etc. are thinking and planning; these guys are just punk kids with a problem with people they don't like and are not scared of getting caught.
They know they are going to get away with this crap, what sort of description do police have to work with? "It was a couple of ***** teens, officer."
Like you said, that describes a whole lot of the people walking around at that time of day, or night.
Remember those teens who shot the Australian athlete Chris Lane "Just for fun" a couple of months back? Guess what one had been doing with his friends the week before?
"knocking out woods" AKA playing the knock out game.
Do you know what a "wood" is? It's from the prison slang name Peckerwood. A Peckerwood is a white guy that will fight to protect himself in jail.
http://www.thegatewaypundit.com/2013/08/oklahoma-thug-shooter-tweeted-about-knocking-out-peckerwoods-after-zimmerman-verdict/
When you understand whom it is that is doing this, what their motivation is and where they hang out
it is actually pretty easy to spot them and stay clear of them.
You are not just looking for the "group" of them, they don't mind sucker punching a person from behind when it's one-on-one.
You guys have seen the video of the lady walking past the ATM?
She got knocked out by only one of them, from behind, of course.
I have been looking for a way to break it down without going un-politically correct but you
just can't talk about what they are doing, why and whom they target without the race issue coming up.
Even police departments have had to, reluctantly, look at the race motivation in these attacks.
Google, read and understand the whom and why and you'll find plenty of articles explaining it; adjust your behavior accordingly...
I don't believe you can develop good defensive tactics without understanding just what the threat is.
Why they want to attack you is part of understanding the threat and from whom it is coming.
It sucks but there it is...
How does that line go? "We didn't start the fire..." We do have to deal with the flames though.