From: "Rich Gauszka" 

Do they have to have special FCC approval to jam or do they use the passive
(legal) block?

http://electronics.howstuffworks.com/cell-phone-jammer5.htm

In the United States, United Kingdom, Australia and many other countries,
blocking cell-phone services (as well as any other electronic
transmissions) is against the law. In the United States, cell-phone jamming
is covered under the Communications Act of 1934, which prohibits people
from "willfully or maliciously interfering with the radio
communications of any station licensed or authorized" to operate. In
fact, the "manufacture, importation, sale or offer for sale, including
advertising, of devices designed to block or jam wireless transmissions is
prohibited" as well

Jamming is seen as property theft, because a private company has purchased
the rights to the radio spectrum, and jamming the spectrum is akin to
stealing the property the company has purchased. It also represents a
safety hazard because jamming blocks all calls in the area, not just the
annoying ones. Jamming a signal could block the call of a babysitter
frantically trying to contact a parent or a someone trying to call for an
ambulance.

The Federal Communications Commission is charged with enforcing jamming
laws. However, the agency has not yet prosecuted anyone for cell-phone
jamming. Under the U.S. rules, fines for a first offense can range as high
as $11,000 for each violation or imprisonment for up to one year, and the
device used may also be seized and forfeited to the government.

While the law clearly prohibits using a device to actively disrupt a
cell-phone signal, there are no rules against passive cell-phone blocking.
That means using things like wallpaper or building materials embedded with
metal fragments to prevent cell-phone signals from reaching inside or
outside the room. Some buildings have designs that block radio signals by
accident due to thick concrete walls or a steel skeleton.


"Glenn Meadows"  wrote in message
news:45b813e7$1{at}w3.nls.net...
> Jamming/block.  Like many theaters are doing now.
>
> I walk into a local cinema, and my cell phone goes from full 6 bars to no
> service, in the space of 50 feet, from the lobby to into the theater
> itself.
>
> --
>
> Glenn M.
> "John Beamish"  wrote in message
> news:op.tmotcikpm6tn4t{at}dellblack.wlfdle.phub.net.cable.rogers.com...
>> On an etiquette issue:  I've heard that some commuter trains in NY have a
>> "no cell phones" permitted.  True?  False?  How is it done?
>>
>> On Wed, 24 Jan 2007 20:54:39 -0500, Rich Gauszka
>>  wrote:
>>
>>> "Table for two? Will that be cell phone or non-cell phone?"
>>>
>>>
>>> http://www.timesonline.co.uk/article/0,,2-2556550,00.html
>>>
>>> Could these be the cigarettes of the 21st century? . . . 'Absolutely'
>>>
>>> # It's right to have worries, says expert
>>> # 'Don't buy phones for primary pupils'
>>>
>>>
>
>

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