What does Spy gate have to do with Denver Broncos scandal?

Most likely because Josh McDaniels is a former offensive coordinator for the Patriots. Remember the whole "spy gate" term originated a few years back when Belichick was caught spying on the Jets defensive signals, and they attempted to use that information. But they were caught in the act thus considered cheating. In terms of McDaniels, it was pretty much the same thing. I guess many fans in the NFL link McDaniels to what happend with the Pats because of him being a former coordinator there, and some figure Belichick must produce "cheaters".