There are lots of dangerous places in the US.
The lower-class areas of all large cities are dominated by gangs and drug addicts, making any venture
involving expensive equipment potentially hazardous with a real possibility of theft or assault.
A few years ago during a 10km Folksmarch in Baltimore, two of the participants were robbed in broad daylight in the downtown area.
The best defense is staying in areas with numerous pedestrians. It's no guarantee of safety, but it helps.