There are several threads about this and basically the idea is that Cancun and Riviera Maya are hundreds of miles (if not actually over 1000 miles) away from the dangerous border towns. So it is like saying you are not going to visit Nashville, TN because there are murders in New York City. And like mmcst38 said, there is just as much violence in the US. I hate to make this reference, but how much more dangerous is leaving your resort in Cancun, Mexico than going to the grocery store in Tuscon, AZ? As long as you keep your eyes open and use common sense (as you would in any American city), then you will be fine. You need to do what will make you happy for your wedding. If that means having your wedding in Mexico, then all you can do is try to educate your families. Best of luck.