Turns out maybe I was doing something "wrong" in photographing the bridge construction site.
I just heard that the FBI tracked down a friend of a friend who had been shooting pix at the river. They told this person not to photograph refineries, power lines, or anything that might be a terrorist target.
The MN Dept. of Transportation must be exempt from this restriction. It tells us all about the bridge construction at:
MN DOT Bridge Project
Nevertheless, if the FBI's Men in Black ring my doorbell, I'm definitely sending Kirk, not me, to answer the door.