Is this flag quickly and easily removable? If not, I can think of many situations where it might be a safety hazard. What happens when you come around a corner and there's a pedestrian standing right in its path?

After a close call a few years ago with a landscape truck pulling an empty flat bed that was swerving all over the road, I carried a hand-held flag on my top tube for a while. It worked pretty well until I lost it. Of course, this only extended as far as my arm and could be retracted on a moment's notice. Sorry, but your flag looks like an accident waiting to happen.