Chris Brown's Neighbor Problem -- Come on My Property, I'll Shoot You

Chris Brown may have new, more troubling neighbor issues ... we've found out he's moved deep into the San Fernando Valley, and one of his new neighbors is threatening lethal force if Chris steps onto his property.

Real estate sources tell TMZ ... Chris is renting an 8,000 square foot, 6 bedroom house in Agoura ... it's near the Malibu border but technically part of the Valley.

It's a pretty sick pad. It has a commercial ice cream bar, dance studio, billiard room, as well as a tennis court and clubhouse.

Chris likes ragers -- he had one over the weekend -- and there's plenty of space to park 75 cars.

Now the problem. We spoke with one of his neighbors, who said flatly, "It can be the devil. I can care less. I don't care if they're having orgies. It can even be Saddam Hussein for all I care, as long as he doesn't trespass onto my property. If he does, I shoot him."