US law enforcement have access to vast networks of surveillance cameras

Examples
Date

When Dallas police posted on Twitter asking for videos of the protests taking place after George Floyd's killing, a flood of videos and images of K-pop stars were uploaded to its anonymous iWatch Dallas tip-off app. Law enforcement can call on vast numbers of networked cameras - from cars, food and retail chains that are typically willing to share with police, law enforcement agencies' own networks of surveillance and body cameras as well as object and face recognition software, protesters and journalists' smartphones and small cameras, and Amazon's Ring and Google's Nest positioned outside homes and small businesses. Software analyses the video footage to spot movement or people. However, the many cameras watching allowed George Floyd's killing to capture national attention.

https://www.washingtonpost.com/technology/2020/06/03/cameras-surveillance-police-protesters/

Writer: Heather Kelly and Rachel Lerman

Publication: Washngton Post