In public, you already know how to identify these kids. Unfortunately, online, there are two extreme.
1. Look for the person that seem to be using words that are meant to sound poetic and appear as though they've just freshly been looked up on thesaurus.com.
2. If not that, look for sentences and phrases that are mind-numbingling and purposefully incorrect in grammar. This can often distinguish males from females. When in doubt, look for a lot of 'X'es between their words. This is a very distinguishing factor.
If using a site that displays pictures, expect an angled photograph, likely with hair falling over at least some portion of their face.
Non-scene kid writing a simple profile for himself:
"Hi, my name is Brad an I'm 20 years old. My hobbies are biking, running, and traveling. I also enjoy music on occasion."
Poetically-accurate scene kid writing a profile for himself:
"Hey, my name is Chris and I am forever the unbearing image of a hopeless and deprived generation. The archaic means with which I conduct my activities are meant to express my undying dismay for a system which attempts to destroy my very being; a system in which I refuse to participate. Body modification and music solely encompass my crowded itinerary; if my hand isn't expressing itself on the frets of my acoustic guitar, it's expressing itself through my next tattoo design on paper. I won't even list the artists I listen to...you never would have heard of them."
Ridiculously Simple Scene Kid writing a profile:
"hi, im chelsea and im 19 yo. i enjoy things like idk, music nad drwing adn art dna fashn ndadandandan stuff like that. my boyfriend conor is the love of my life so evry1 else BACK OFF!!! <3 <3 <3 u can see me at shows and at schol evry once in a while as lng as im not skipping! xhardxcorex <3 i listen to a lot of music, but nothing u wuld no, nad uh yah add me adn we cn chat! <3"