Eavesdropping

Eavesdropping : is the act of surreptitiously listening to a private conversation. This is commonly thought to be unethical and there is an old adage that eavesdroppers seldom hear anything good of themselves. [http://en.wikipedia.org/wiki/Eavesdropping]

Is there's a possibility to view others information from 20 metres away with absolutely no connection with the client computers?
well you can.

In a recent research made by swiss research, its publicly notified the feature of eavesdrop others computer data with absolutely no connection with the computer itself.

Each key board, no matter with PS2 or USB any keyboard provide an unique pattern of Electro-Magnetic radiation which can be monitored from an average analog antenna from 20m apart or if you have better equipments, from plenty meters aprt unless any distrotion.

This discovery made a great security vulnerability as any user having the basic equipments (which most of times will cost about 50USD) can eavesdrop information typed from a target computer.

Research further suggest that "Key board is no longer secure against sensitive infomation"