Apparently security contractors have been drilling into trees on public city streets to install signaling hardware to ensure that guards are following their patrol routes. The companies say that the devices enable "guards can prove exactly when, specifically where and what they inspected at a location."

However, the devices are illegal and the New York City Department of Parks & Recreation has been finding them and taking them down. It seems to be a New York thing because it has not been noticed on the other side of the country.

However, it is part of a noted uptick in the use of employer spying devices since the pandemic. Electronic managerial oversight has become an issue at Amazon, prompting unionisation efforts in response to unwelcomed staff monitoring.

A 2020 report from the Open Markets Institute, a progressive think tank, accuses Amazon of harmful worker surveillance practices. And last year, the organization updated its report arguing that Amazon's worker surveillance disproportionately targets low-paid workers and racial minorities.