Per the Kiplinger letter:
Did you know that
marketers are using cross-device tracking to learn all about you? They connect
and track every Internet enabled gadget that you and others use every day. Because
of this tracking Uncle Sam is considering possible regulations.
The Feds want to stop
another new marketing tactic: The Federal Trade Comm. has issued
cease-and-desist letters to app developers that are using your smart phone to
pick up sounds, inaudible to humans, emitted by TV ads. The detailed personal
tracking comes without the viewer’s knowledge or consent.