Good Grief!
I was using ridiculously outdated slang expressions for comedic effect. Obviously I failed.
L7 means square.
You were just tryin’ to be kool, daddy-o! 
23 skid doo !!!
Sorry, been playing GTA:SA way too much lately. Bustas. 
To the OP, yes, discussing the how-to’s of any illegal activity is a big no-no here. For instance you can open a thread saying that you advocate the legalization of marijuana and you want to discuss it; that’s fine. You can discuss risks of using, why you think the laws against marijuana are wrong, and so forth. But you can’t discuss topics such as how to get the highest yield when growing MJ, or the best way to make a bong, or where to score in downtown Hoboken.
In case it’s not immediately obvious, the use of L7 to mean square comes from the fact that “L7” looks vaguely like a square.
The expression’s not completely extinct. James Lileks used it in one of his Bleats not too long ago. (The link just takes you to his homepage, I don’t know how to find the actual Bleat where he used it.)
Spectre: To apply your analogy to my thread, I think it would be the equivilent of asking how THC interacts with neurotransmitters, which I think is kosher according to the rules around here.
You could also open a thread in Great Debates where you advocated changing copyright law to allow P2P copying, or some other system of copyright. But General Questions about file sharing are generally treading on thin ice.