[DDickson]

These devices are typically installed in "high crime" areas. They then detect more crime (Or just loud noises). This calls police to respond to the area, and increased interaction with police commonly leads to increased confrontation with police leading to arrests. Thus re-enforcing the "high crime" reputation of the area.

[david38]

If they worked as advertised, it would be fine. You don’t just uniformly deploy such things. They’re not free.

But like you said, if they just detect loud noise, that’s a problem.