Unfortunately, the good reporting is overshadowed by the slightly alarmist stone captured in the headline: "Threat grows as Mexican cartels move to beef up U.S. presence".
Before you start worrying about a wave of decapitated heads on your front lawns*, it should be noted that, headline notwithstanding, in no way does the article demonstrate a growing threat. What it does demonstrate quite nicely is the existence of something that will surprise no one with a basic understanding of how international drug supply chains work: US gangs, which have for generations sold illegal drugs, have to work with foreign suppliers, since much of the drugs sold in the US is manufactured elsewhere. This passage is indicative:
Unlike the cartel crews in Mexico, which are typically built on strong ties between families or friends, the San Diego franchise recruited from U.S.-based Latino street gangs. Some were illegal immigrants, others U.S. citizens, according to arrest warrants. Twelve of the 43 indicted have alleged gang affiliations in San Diego. Six of the 43 are current or former Mexican law enforcement officers. Eight are women.The bolded part shows how unremarkable this is. Foreign traffickers always team up with local street gangs, both in The Wire and in real life. None of this should surprise or frighten us, at least not any more than it usually does. The stuff that could scare us --such as Mexican gangs intimidating or attacking American cops on American soil, or a FBI office chief being on a gang's payroll, or any concrete sign that this gang is fundamentally different that those that have come before-- is absent.
*As always, Burro Hall also serves as a good antidote for this concern.