Sadly, I think most people's first impression would be fear, also because these children would seemingly be unable to control these newfound abilities. No parent would want to allow their child to be put in the same classroom as one that, at least to their understanding, randomly has these devastating attacks which potentially could kill.
It would just take one accidental death to merit the encampment of such people, however the government's motives would be shrouded with the excuse that the scope is to study them and better understand them. If scientists are unable to have predictable controlled behavior in these people, they will likely never leave these encampments (though there might be visiting hours or else I doubt if the government could get away with this).
The ones that show promise to control will be of most interest to the scientists and they. The government in particular will mostly want to know to whatpush scientists towards the extent canthat these people have to use these powers be used to say, assassinate a target. This information is invaluable not only to wield that power but also to know how to protect against it in the most certain case that other countries have such children in their possession.
Protocols for the secret service would most certainly change. It would no longer be enough to check for weapons. You'd also have to perform background checks on anyone who sees the president (save for political figures, family, and other people who are more trustworthy).
Security checks before entering a plane flight would be a nightmare. If a seemingly normal child got aboard a plane and due to uncontrollable attacks managed to puncture a hole in the plane, the plane would most certainly crash. Before you could purchase airplane tickets, you would probably have to go through a mandatory background screening, and this would be relatively expensive. Other than the cost of the ticket, you'd likely have to pay a tax so that a newly founded government agency could perform a background check just so that you could be able to board a plane.
The country itself would revert to the witchhunt days and the days of "secret" communists. Children accused of having magical abilities would be quickly picked up and thrown into the encampment despite not having actually shown any particular magical ability. The process would be long and difficult to prove that that child never actually demonstrated magical ability in order to free him or her.
In other words, I suspect that everything would become that much more complicated, and this is not even considering the types of things one with magical abilities could perform but only with an uncontrolled "burning ray of light".
If enough magic users came together in one place, they will already naturally loathe being there, and this prejudice would only encourage them to begin to think that they are different than everyone else. It would take little for such people to begin considering themselves superior and to start protesting and rioting.
It would all create a sort of dystopia and not at all like the kind of world you'd think when you imagine the birth of those who could use magic. ;)