Startup uses ultrasound chirps to covertly link and track all your devices
by Cory Doctorow from on (#TGJX)
Silverpush, a startup that's just received $1.25M in venture capital, uses ultrasonic chirps that are emitted by apps, websites, and TV commercials to combine the identities associated with different devices (tablets, phones, computers, etc), so that your activity on all of them can be aggregated and sold to marketers. (more")