The problem is two fold.
One they are extremely poor. Cloths on their back levels they come with nothing besides knock off phones its what they can carry.
Two they can't speak and most can't read and write in their own language never mind the local one.
There isn't a way to control much less help them in such numbers maybe if it was a few hundred a year but it has grown so utterly out of control even containing them to a area is a fruitless task.
Don't get me wrong I can see their lot in life is shit but turning everything around them to shit doesn't help.