If they can put someone on the case at all, they can then select out cases where one user makes multiple threats, for example, or some similar criterion, and wh

If they can put someone on the case at all, they can then select out cases where one user makes multiple threats, for example, or some similar criterion, and where the likely perpetrators can be identified. Law enforcement never tries to catch 100% of criminals, they just need to pursue the worst in each category and publicize convictions to exert a deterrent effect.