
A bar owner in the UK has built a Faraday cage to stop customers using phones - wbsun
http://www.sciencealert.com/a-talented-bar-owner-in-the-uk-has-built-a-faraday-cage-to-stop-customers-using-their-phones
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onion2k
He's committed a crime that means he could face up to two years in prison.

"The use of any apparatus, whether or not wireless telegraphy apparatus, for
the purpose of interfering with any wireless telegraphy, is an offence under
the Wireless Telegraphy Act 2006. It is an indictable offence that on
conviction in Crown Court carries a maximum penalty of two years imprisonment
and/or an unlimited fine. The courts can also order forfeit of any apparatus
used in the commission of the offence."

[http://stakeholders.ofcom.org.uk/enforcement/spectrum-
enforc...](http://stakeholders.ofcom.org.uk/enforcement/spectrum-
enforcement/jammers/)

~~~
dalke
A Faraday cage is not a jammer. As the article points out:

> Faraday cages are different from electronic jamming devices, which work by
> actively blasting out an electromagnetic signal that stops someone from
> receiving radio waves.

> Those jamming devices are illegal, but Faraday cages don't break the law,
> seeing as they passively filter out phone signals - although you can imagine
> that blocking all phone reception at the pub isn't something that would go
> down particularly well.

The article also points out, "You most likely have a type of Faraday cage in
your house right now in the form of your microwave. That metal mesh you can
see in between the glass in the door is there to stop microwaves from
escaping."

Any metal container acts as a Faraday cage, including metal vessel hulls.
Obviously these are not all banned by the law you pointed out, which only
applies to a wireless telegraphy station, or wireless telegraphy apparatus.

~~~
onion2k
Building a Faraday cage _specifically to block phone signals_ is a very
different act compared to building a Faraday cage. It's the "to block phone
signals" bit that makes it illegal.

~~~
dalke
Here is the law:
[http://www.legislation.gov.uk/ukpga/2006/36/section/8](http://www.legislation.gov.uk/ukpga/2006/36/section/8)

It refers to "telegraph station" and "apparatus". A Faraday cage is not a
telegraph station, so it must be an apparatus to be covered under that law.

What does that mean? I think it's defined in
[http://www.legislation.gov.uk/uksi/2016/426/regulation/3/mad...](http://www.legislation.gov.uk/uksi/2016/426/regulation/3/made)
:

> “apparatus” means any finished appliance or combination of appliances,
> liable to generate electromagnetic disturbance, or the performance of which
> is liable to be affected by such disturbance, and which generates, or is
> designed to generate, or is liable to generate fortuitously, electromagnetic
> energy at frequencies not exceeding 3,000 gigahertz and includes—

> (a) components or sub-assemblies intended for incorporation into an
> apparatus by an end-user, which are liable to generate electromagnetic
> disturbance, or the performance of which is liable to be affected by such
> disturbance;

> (b) mobile installations defined as a combination of apparatus and, where
> applicable, other devices, intended to be moved and operated in a range of
> locations;

Are you arguing that a Faraday cage is a "finished appliance or combination of
appliances"? And it "generates, or is designed to generate, or is liable to
generate fortuitously, electromagnetic energy"?

If not, then it is not an apparatus, and so not regulated under the law you
pointed to.

If you still think it is illegal, then please cite the actual law, and not
some commentary about the law, as commentaries are more open to
misinterpretation.

~~~
wlesieutre
It generates electromagnetic energy in the same sense that noise cancelling
headphones generate sound. The net effect is that it interferes destructively
with the original incoming waves, never adding on to them. Whether that
legally counts as generating interference, I have no idea.

(all that assuming I actually understand how Faraday cages work)

Addendum: maybe "generates" isn't the right word, since noise cancelling
headphones make their own sounds from a power source, while this is totally
passive redirection. You wouldn't say a mirror generates light, after all.

~~~
dalke
Your addendum is correct. A Faraday cage is much more like a passive mirror,
or sound absorbing foam, than it is an active, powered, noise cancelling
headphones.

------
Pfhreak
This feels a bit myopic to me. I rely on my phone to do all sorts of things
that I need to get notifications for, even when I'm socializing.

I totally understand the desire to avoid having cell phones out during a
social event, but I'm not sure it's the venue's responsibility to enforce
social convention -- especially in a way that could impair critical
services...

~~~
lj3
Then don't frequent that bar. It is absolutely the venue's prerogative to set
the atmosphere in any way they like that doesn't violate the law. The
customers vote with their dollars. Time will tell if there's enough people who
value a tech free social experience to keep the place running.

~~~
SerLava
>Then don't frequent that bar. The customers vote with their dollars.

You're talking like he was suggesting beating the bar owners to death. He just
said they shouldn't set up the cage.

>Taking a shit on the bar sounds rather unappealing

Then don't frequent that bar!

------
kevin_b_er
The article appears to have some sort of bad science.

> This effect was first discovered back in 1836 by physicist Michael Faraday,
> and it works in a similar way to noise-cancelling headphones, which block
> out noise by emitting the opposite wavelengths of sound.

> So, when electromagnetic radiation - such as a phone signal - hits the
> outside of a Faraday cage, it causes electrons in the metal to move and
> create an electromagnetic field that exactly opposes and cancels out that
> wavelength of radiation.

They make it sound like the mesh is actively generating an opposing signal to
cancel out the cell phone signals, which is pretty far from the truth. I think
the article writer looked up info on how faraday cages use charge imbalances
and then figured they were just like active noise cancellation headphones..
somehow.

