There are already in place many automatic license plate readers on things such as road signs and bridges. This has purposes for helping track vehicles known to be owned by criminals, but simultaneously the tracking information is stored for millions of innocent people as well.
Essentially, this paper goes through the types of gait recognition software that currently exist as well as the reliability of this software. There are a lot of different elements that influence a persons gait (like terrain, shoes, fatigue, etc.), which effects how well the software works. It's a pretty heavy read but it's really interesting if you want to just jump to a certain section and read in depth. This technology is very much out there and in development, and it is definitely being improved upon.
Also, even though this paper is a little bit older, it is still being cited in a lot of more recent research papers and I thought it would give a good enough grasp on the science for our purposes.
An app circulated among the protesters in Hong Kong that supposedly was for coordinating protest efforts, but was in reality a phishing attack that would track keystrokes, messages, and identity information of devices it was installed on. Many signs point to the Chinese government as the origin of the malware, though. Not the first time a government has done something like planting spies and monitoring protestors. We saw this in Little Brother too, with the DHS spies on the Xnet.
After a high school principle pulls the plug on a plan to use Little Brother as a common reading, Cory Doctorow sends the school 200 copies of the book for free. Good man.
This article, though very clearly biased, describes the ways in which the movements of citizens are being tracked by both technology and the police. The video/information slides are obviously carried out with bias, but the information is still there. The end of the article has some interesting (helpful?) information about what the judicial system is ruling on cases involving location tracking without warrants.
High school student suing Philadelphia's Lower Merion School District for remotely accessing his webcam. And maybe you read the Superintendent's response and thought, "well, maybe this whole business is getting blown out of proportion." It isn't.