I have to play devils advocate here. In 2010 the same question was asked so...
why are my respected and trusted sources even covering this? Well the census is "usually" used to determine how congressional seats are rationed by our totally trustworthy Mommies and Daddies. Shh Shhh its okay, just give me some DNA so I can prove you're not mine and send your ass packing!
The new fear is that this information would be used to comprise a list of Cannon Balls to launch over the figurative wall we have. Well, if you are undocumented, I'm sure you have figured out to dodge the occasional Gubmint paperwork. So is this another fear tactic? The same argument was taking place in 2010. So I'm thinking Undocs didnt have a worry in the world in 2010? I would say to them, check the deportation #s during Obama.
BTW, if my complaint was, "theyre gonna catch me" why would I want to make that a viral topic