The Mexican Mafia has significant operational control only within prisons, yet manages to tax street gangs at rates of 10-30% of revenues. It has become a kind of government. A PDF of the corresponding journal article exists here.
You mean there's a war, and people on drugs are winning it? The latest additions to the Gruaniads special report on drugs are interesting. In the top story Scotland Yard is endorsing a more relaxed attitude towards cannabis possession. Nick Davies has written a series of two articles, mostly focussing on heroin, about how drug prohibition actually increases the spread of illegal drugs and causes most of the related health problems. Looks like legalisation is good for everybody.