OK, this article freaks me out.
Like several commenters noted, I too would be scared to stop if someone in black just yelled at me to stop. No identification, no, "Stop, Police!" or anything like that. Hell, I've been yelled at many times and just keep on truckin', more for self-preservation than anything else. So now what? No riding at night? Sure, PDX is a Platinum city, but our cops are not on-board with that.