Pretty daft, but I can suppose you can imagine how it might happen. It's east enough to look suspicious. I always seem to get searched going through the checks at airports.I think it's the beard.

Less excusable is the case I came across online about a father in Tennessee who got arrested because he wanted to collect his child from school on foot instead of doing it with a car or letting them catch a bus.
See here for details of that curious incident.