EDIT
To those insisting on calling this a cage, I hope you realize that every jail in the world looks like this. These people (not children in the picture) are under arrest for illegal immigration. They are going to be detained somewhere.
The CBP is uncomfortable with reporters using the term "cages" but have stated that it is not an inaccurate description. -CBS morning news.
I linked above to a photograph for you showing young children (not adults) kept in the same cages.
Even if you don't care about the adults, young children are blameless. In every other type of case like this, when an adult commits a crime and their child is with them, the child is placed in temporary foster care until more suitable accommodations can be found. They don't get taken from their parents and stuck in a metal cage for weeks on end.
The only reason to call it something else would be to pretend it's not a cage.
I take it you haven't seen the video footage of these places yet?
personally i think i'd prefer the cheap fencing material, as it would allow for better ventilation.
...You're aware this is actually happening, right? Here's BBC on the matter: https://www.bbc.com/news/world-us-canada-44518942