By Rick Jervis
The violence among Mexican drug cartels is not filling just the streets of Mexican border towns: It's also spilling into gruesome online videos and chat rooms.
The videos on YouTube and Mexican-based sites are polished -- professional singers croon about cartel leaders while images of murdered victims fade one into the next. In the comment area, those loyal to the opposing cartels trade insults and threats.
Cartels, gangs using Internet to recruit