I think anti-languages are something that evolve naturally, not necessarily because of a specific requirement -- like talking about criminal activity. It's just lingo really, look at any online community and they all have their own language which is born of convenience and familiarity.

My wife and I have our own of sorts, where words have been bastardised, such as computer -> computner -> putner, or where specificity is given through context, dooper -> remote / phone / thermometer / keys.