In this case, this is actually a potentially useful military technology, specifically what is called the Unattended Ground Sensors (UGS) system.

These are a family of disposable/deployable sensor ranging in size from something a bit smaller than a shoe box to about the size of a cigarette pack:

The UGS come in two forms, the Tactical UGS and the Urban UGS. Tactical have four different versions, including the ISR node, which contains magnetic, seismic, and acoustic sensors; the Gateway node which is a communications relay system; an Electro-optics node with an EO camera for the day and an infrared camera for night; and a Radiological/Nuclear node. The Tactical UGS are about a foot long and several inches wide (exact specs are classified), and are typically partially buried so they aggressor units can’t see them while passing by. Urban UGS are smaller, and are placed on walls inside buildings to monitor rooms already cleared by soldiers. The two UGS send data back to the Gateway, which then processes the information and send its out through the FCS communications system.

The basic objective of the technology is to create a networked picture of the battlefield.

Situational awarness is frequently the most important part of winning a battle, but when one considers that any foreseeable conflict in the immediate future will be a counterinsurgency operation, where US forces would be operating at an information disadvantage that will not be helped by this sort of technology.