Together, these young men are a kind of river-one that is out of control, eating at the foundations of things we hold dear: our freedom to move about; the fruits of labor; our own lives and those of people we value. (Para. 32)
Meaning: These young men joined to form a kind of river, the river that is impossible to manage, and that is bit by bit damaging the ideas that are beyond value to us: our freedom to move about, the fruits of labor, our own lives and lives of people we have high a opinion of.