I'm sensitive to the possibility that government actors might receive threats. Threats are wrong.
But the government should be held to certain standards in their interactions with the governed. They include transparency and accountability, and they are of particular importance when the government is attempting to deprive someone of their freedom. Anonymous government actors - with no uniform, agency identification, badge number, name, or face - are not transparent or accountable to the public. A democratic government's legitimacy is rooted in the consent of the governed. Consent requires knowledge. Anonymous state action frustrates knowledge.
The government should fear the people, not the other way around. Weighing the interest of some government actors to avoid the potential for threats against the interest of the general public in understanding what its government is actually doing, I come down strongly on the side of the general public.