As terrifying as the Holiday Inn invasion must have been for all guests, the reality is that nobody who wasn't involved was kidnapped. I travel to MTY all the time (4 days/month) and yes - it's on my mind. That said, assuming you have no connection to the narco biz, I don't think you have much to worry about in Monterrey. The "random" crime has been minimal. Two Monterrey Tech students were killed in the crossfire a few weeks ago - which is tragic - but the exception and not the rule.