Big Brother is listening as well as watching

In a world of ubiquitous security cameras, most people know by now that some form of Big Brother – government or private – is watching them. But they are less likely to know that in some areas, he is also listening.
While it is not yet widespread, audio surveillance is increasingly being used on parts of urban mass transit systems.
That is the bad news, in the view of privacy advocates. But the good news is that public awareness can, at least in some cases, curtail it.
This past wee