I had a flagging job one day last week. Periodicaly during the day, a truck would be partialy blocking traffic while unloading "ecology blocks". Hence, flaggers needed. So, I always have a small "daypack" with me that holds raingear, water etc. I had the pack setting along the road near me. However, my duties would sometimes cause me to be quite a distance from it. I was about 1/4 mile south of canada on the "truck,commercial traffic" road that leads to customs. Lots of cops and border patrol cars in the area. At one point a BP stopped and asked a worker if he knew who belonged to the pack, pointing to my pack sitting alone along the road with me nowhere in sight. Luckily the cons't. worker knew it belonged to me and told the BP not to worry.
I'm sure it had to do with the vicinity of the border.
So, no bomb squad or SWAT was called out that day.