You can leave the earpiece behind and stand a few feet away while someone is recorded on your home answering machine.
Also, those two-way family radios have a range of 2-5 miles.
Some of them can be voice-activated.
And have you ever heard just how well some baby monitors can pick-up every sound in a whole house?
Digital voice recorders-- also voice activated-- can record something like 30 hours of sound.
Put a transmitter (voice activated?) somewhere and mate the receiver with a digital voice recorder in the bushes and come back at your leisure.
You'd also be surprised (or not) to see how many people have their computer monitors facing the windows of their offices.
Digital cameras (and camcorders) have a remarkable zoom capability.
And forgetting for a moment about relying on technology, get a copy of The Art of Deception by Kevin Mitnik.
Good old fashioned Social Engineering goes a long way.
The Art of Deception: Controlling the Human Element of Security
by Kevin Mitnick
ISBN: 0471237124
Synopses & Reviews
Publisher Comments:
Kevin Mitnick‛s exploits as a cyber-desperado and fugitive from one of the most exhaustive FBI manhunts in history have spawned dozens of articles, books, films, and documentaries. Since his release from federal prison in 2000, Mitnick has turned his life around and established himself as one of the most sought-after computer security experts worldwide. Now, in The Art of Deception, the world‛s most famous hacker gives new meaning to the old adage, "It takes a thief to catch a thief."
Inviting you into the complex mind of the hacker, Mitnick provides realistic scenarios of cons, swindles, and social engineering attacks on businesses–and the consequences. Focusing on the human factors involved with information security, Mitnick explains why all the firewalls and encryption protocols in the world will never be enough to stop a savvy grifter intent on rifling a corporate database or an irate employee determined to crash a system. He illustrates just how susceptible even the most locked-down information systems are to a determined con artist impersonating an IRS agent or any other seemingly innocent character. Narrated from the points of view of both the attacker and the victim, The Art of Deception explores why each attack was so successful–and how it could have been averted–in an engaging and highly readable manner reminiscent of a true-crime novel.
Most importantly, Mitnick redeems his former life of crime by providing specific guidelines for developing protocols, training programs, and manuals to ensure that a company’s sophisticated technical security investment will not be for naught. He shares his advice for preventing security vulnerability in the hope that people will be mindfully on guard for an attack from the gravest risk of all–human nature.
More:
http://www.powells.com/biblio/17-0471237124-1