

Local Police Want Right to Jam Wireless Signals - mattmcknight
http://www.washingtonpost.com/wp-dyn/content/article/2009/01/31/AR2009013101548.html?hpid=artslot

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jhickner
I think it would be incredibly dangerous to give police this power.

Once always-on, instant-upload digital recording equipment becomes
commonplace, it will hopefully spell the end of abuse by police officers. They
won't even be able to confiscate your camera to hide the evidence anymore,
because the content will already be online.

But if police can just shut off your wifi, we're back to square one.

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steveplace
I am familiar with the technology and have worked on it directly with one of
the companies mentioned in the article.

It was originally designed for CT measures in Iraq, since roadside bombs were
being detonated by remotes on GSM and CDMA bands.

That people want to carry it out to this extent frightens me. Big brother
aside, it limits our ability to use 911 services (unless you specify a certain
reject code to kick the phone to emergency mode).

We seriously need to put local and state governments under scruitiny when it
comes to using cellular exploits such as these. Cellular protocols are not
secure at all so any attack you can think of is plausible (intercept,
tracking, man in the middle, etc). I don't know what sort of precedents that
there are for other communication mediums, but we need to develop a sensible
legal framework within which to work when dealing with these technologies.

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kogir
So, at least with bombs, wouldn't jamming devices allow for better targeting?

For instance, if I know jamming is employed, I could create a trigger that
detects the jamming (not very subtle and only available to the military), and
goes off when the jamming intensity starts to decline.

This would allow the bomb to go off right as the jamming device passes,
causing maximum damage, no?

NOTE: I would never build such a device.

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steveplace
That's not how cell phone jamming works; it's not a real "jam" of all
frequencies. I don't know how much detail I can get into, but essentially you
pretend you're a base station and you disallow all calls to that phone.

So your trigger would have to be much more intricate than that.

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mkn
To me, that article was an amazing technical achievement. The author went on
for three pages about police seeking the right to jam cell phone signals, and
not once did they mention the ramifications for the ability of the populace to
hold the police to account for abuses. And they did so less than two weeks
after damning cell phone video of the execution of a civilian by a police
officer on the BART system.

While I would admire the author's technical skill in skirting the issue (truly
amazing), I now have even deeper reservations about the editorial policy and
institutional bias of the Washington Post. While many of the participants at
HN write very lucidly, I wouldn't guess that many of us have worked as
writers. I have, and I could not have _designed_ a piece of writing to better
omit the issue of civilian surveillance of law enforcement officers given the
subject matter they were handling.

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cgranade
From the article: _Police and others say it could stop terrorists from
coordinating during an attack, prevent suspects from erasing evidence on
wireless devices, simplify arrests and keep inmates from using contraband
phones._

Now how in the heck is an RF jammer going to prevent the erasing of evidence?
I guess if the evidence is stored remotely, you can't send the kill signal or
something, but that falls so far into movie-plot terrorism that it isn't even
funny. If the police asking for these kinds of new sweeping powers can't even
get such a simple technical point right, then why should we trust that crime
prevention is the true objective or that they are competent enough to have
these powers?

Now don't get me wrong-- there's a lot of good cops out there. I think that
these kinds of problems are systematic and not individual.

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likpok
The main issue with this is that remote bombs do not seem to be a big issue in
the US. So we are giving away our freedoms for what amounts to scaremongering:
there's no actual reason to use it outside of very few high-profile targets
(and maybe not even then).

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vaksel
and its not like they need a cell phone to remotely detonate stuff...they can
always lay down a wire and detonate it that way.

Or a pressure sensitive switch.

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tomjen
Or blow it when it stops receiving signals.

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mattmcknight
I have met the local police, and I don't trust them with this responsibility.
I am sure the Blackberry slinging FBI won't want to let them do this either.

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Rod
I believe the discussion should not be whether the Police should have the
right to jam wireless signals or not, BUT under what conditions and what kind
of jammers should the Police have the right to operate.

Boundaries must be clearly defined. Jamming wireless signals in a small area
may be a good idea. Jamming an entire city, for instance, would arguably be a
blatant example of abuse of power.

On the other hand, it seems that all that potential terrorists would have to
do would be to use spread spectrum techniques and operate on frequency bands
not used by commercial devices. There's a lot of room for everyone in the EM
spectrum.

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mattmcknight
Good point, the potential for it to be used to block innocent people from
communicating is far greater than any real usefulness against people using
cell phone bomb triggers- which isn't that common.

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Rod
Anyone who has the technical know-how to build a remote-triggered bomb has the
technical know-how to build a jam-resistant system. RF jammers can't possibly
jam all the EM spectrum, and any evil-doer would easily be able to break this
"security" measure.

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evgen
_I_ can build a remote-triggered bomb, but I am not going to be building it
using a spread-spectrum frequency-hopping or ultrawideband trigger because I
am not a RF hacker. This does not make the distribution of jamming equipment
to local law enforcement justifiable, but let's keep the discussion grounded
in reality. Remote-triggers for bombs that use common off-the-shelf RF tools
exist and are well-documented, ones that are jam-resistent are not common (if
they exist at all...)

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thwarted
Perhaps the reason that jam-resistant triggers are uncommon is because there
is no need for them. If signal jamming does become common, then jam-resistant
triggers will be common, off-the-shelf, and well-documented.

