So I'm taking a picture of a really cool front door facade. Beautiful, simple, clean architecture. I'm framing things just right and some DUFUS comes into the picture, sits down, lights a cigarette, and starts to talk on his cell phone.
This is the down-side of operating in stealth mode. I am invisible. Of course, if you know I'm there, you can see me, but most don't notice the guy on the bike in the background. This guy certainly didn't notice me taking this picture.