Those are the new 5G towers that are going up everywhere.Children aren't generally the ones doing the buying and selling. But, for the parents, they will be told that food & much-needed medication for their children can only be obtained by parents who have the mark.
Side Note: In our very rural area, there are huge towers with small satellite-looking attachments near the tops being installed all over the place. Cell phone signal towers? Anti-christ surveillance towers? Or eventually both?