A lack of anonymity discourages crime, of course... but no doubt you know that. Truthfully, we are lucky in that the majority of the ones brought here are decent enough people, and the few exceptions have little to gain by not cooperating.
With that said, it is next to impossible to manage to actually organise even such a small number of people.
[He's tried. Either Sebastian's unaware he's now counted among the people who need to be supervised, or he just disagrees with that notion.]