The issue here is not a technical failing or a bad policy on the library's fault -- the problem is we've allowed this sort of thing to go unpunished so often th

The issue here is not a technical failing or a bad policy on the library's fault -- the problem is we've allowed this sort of thing to go unpunished so often that the perpetrators (correctly) view it as being nearly risk-free. Have the FBI or some other well-resourced and knowledgeable law enforcement agency start investigating these threats and making high profile arrests that result in long prison sentences and I suspect the problem will dry up rather quickly. Unfortunately, the local PD (making the generous assumption that they even care) are simply not capable of tracking down threats delivered via telecommunications even if the threats originate from their own community.