in italy certain clans use some sort of "secret language",which is different between the clans.altough criminals in general and members of organized groups in particular use coded talk to keep civilans and police out of their conversations, traditional oc groups have developed very unique ways to communicate. for example there was(is?) the Baccagghju of the ndrangheta.its a form of the calabrian dialect.The state attoney who investigated the la torre clan of the camorra,described the talks of the imprisoned boss and members of the clan as a secret mixture of slang and gestures and mimic,which was allmost impossible for law enforcement to decrypt.
also i read in a newspaper,that there was a case of mobsters sending messages to tv show from prison and the tv show broadcasted them in continuous text(like in the news).