Masskjutning i Las Vegas - minst 50 döda (2017-10-01)

Public access laws, such as the Federal Freedom of Information Act and its equivalent in most states, almost always allow police to withhold information while investigations unfold. The reason for this, at least ostensibly, is that disclosing information about ongoing cases could compromise what police are doing. People are investigated all the time without being charged, for example. If every lead in every case was made public, the possibilities for slander and libel would grow exponentially.

Along these lines, some cities do encrypt police radio communications so that they can't easily be intercepted by a run-of-the-mill scanner. Pasadena’s police, for example, have been encrypted for over a year.

There was some discussion — and a late 2011 public hearing — in Washington D.C. about its decision to have scanners go quiet. Police argued that criminals were using scanners to plan crimes and that public information officers had other means of informing people about whatever police events were occurring. Local media got upset, but, really, it’s up to police whether they allow scanners to be public or not. Scanners in Ft. Collins, Colorado went silent just this month.