The first time I saw one of these it was in south Texas. I was told it was a Mexican sort of thing and very common there.

This was about 50 years ago so they have been in the US at least that long. I don't really see them as a problem.

The Highway department in Texas lets them stay up for a few months and then removes them. It is all handled in a very calm sort of way since the folks that place these seem to realize they cannot stay up forever.