Wait, shit, that wasn't some random person, that was his technical uncle. This just lends more credence to the idea that this is clearly a Stand-generated world or something to that effect.

He stops once he gets close to Josuke, pausing to take a look back. "I don't know - we need to find out how to make them stop, and to do that we should locate the user," he explains, with a subtly annoyed look. "Though that's easier said than done."