Tadej, Jonas, and MVDP vs Fans - How Should Fans Interact with Pro Riders?

We've had lots of interactions over the years between fans and pro riders (to varying degrees of disaster), from training rides, to during races, to hotels in the middle of the night. As a rider, a fan, and a resident of Los Angeles where I've seen a lot of celebrity interactions I've seen and been on all sides of this, and thought it would be worthwhile to discuss where the line is for fans, as well as common sense best practices for pros.