Cell Phone Jammers: Coming To An Event Near You?

DarwinDan writes "The L.A. Daily News has an article about Cell phone jamming to prevent terrorists from detonating bombs remotely. Jamming technology is already being used "to protect President Bush." An interesting quote from the article: "Public safety is more important than public convenience.""

Comments

"Convenience" versus safety

[JessLeah]

A wise man once said "Those who would give up essential liberty for temporary safety deserve neither liberty nor safety."...

Of course, it's only arguable that cell phone usage is an "essential liberty", but then again you can argue just about anything on the Internet ;)

Re:"Convenience" versus safety

[3Suns]

The problem is in the precedent it sets. Once the public gets used to cellphone "dead zones", people will start using jammers in other areas for other reasons. How about at a movie theatre or concert? A fancy restaurant?

Another jamming cellphones doesn't just cause a problem by preventing citizens from dialing 911. Many public safety personnell, like detectives, part-time police, and firefighters are on call for duty via their cellphones or pagers. What happens if they can't be contacted in an emergency?

Re:"Convenience" versus safety

[surprise_audit]

The police have this nifty gadget called a radio..

Which raises an interesting point - is this a broad spectrum jammer, or just cellphones?? You can get:

1) low power walkie-talkies in Walmart for a few bucks. Range is maybe 100 yards, which would be enough.
2) radio control for model aircraft. Range is 1/2 mile or more and it would be really easy to make a servo operate a switch.
3) it really isn't very difficult to make a spark-gap transmitter, with a wide-spectrum frequency range.

Any of those would be sufficient to remotely trigger an explosive device. And over at Scitoys.com there's a very simple design for a laser communicator made from a laser pointer and a solar cell...

What about 911?

[MKalus]

Isn't THAT safety as well?

Besides, if someone wants to detonate a bomb they will find a way, and if they have to press the button themselves.

I can picture it now...

[adam mcmaster]

"Oh my! That looks like a bomb! I'd better call 911...wait, why isn't my phone working?!"
...Followed by an explosion a few minutes later.

How terrorists will respond to this

[DrXym]

Change code from:

IF kaboomSignal THEN
blowup
ENDIF

To:

IF NOT dontKaboomSignal THEN
blowup
ENDIF

yeah, and does this jammer

[way2trivial]

block pager frequencies?

walkie talker freqs (49 mhz)

block fm radios?

block am radios?

block ham radio?
block light?

unless it's a faraday field in a box, part of the EM spectrum will get through... boom

to paraphrase lelo, bada boom..

Re:really safer?

[betelgeuse-4]

An explosion at a Glasgow factory last week caused the building to collapse, and some of the people trapped inside managed to contact the emergency services by cell phone, making them easier to locate. There hasn't been any suggestion that terrorists caused the explosion, but if a jammer had been in place and had survived the explosion, more people may have died.

Re:Another act in "security theater"

[The FooMiester]

Agreed. "Security theater" indeed. This is because there isn't much the government can do to stop terrorism. The "War on Terror" is fuzzier than the "War on Drugs", because terrorism is more dynamic a concept.

And yes, creating a radio controlled detonator is pretty easy.

If they're doing cellphone jamming, it'll actually make detonators more reliable on other frequencies. There won't be that RF burst when a call is taken and the mic on the phone is opened. Which means less premature explosions.

Also used for silencing theatres and such

[rastakid]

I read a while ago about this technique also being used to switch off mobile phones in places like theatres, cinema's and churches. So, it has yet another 'feature' for the public.
I don't want to be interrupted by a ringtone while watching Van Helsing, but I think switching my Nokia to 'silence' enables this far enough, I don't need help from others silencing my cellphone.

No RF Needed

[faqmaster]

The cell phones used in the Madrid bobmings were used for their timers. That's why they found one undetonated bomb, the clock read PM instead of AM. None of the bombs were detonated via recieving a call.

Rather tha Jamming:

[R.Caley]

I read, I think in New Scientist, a proposal that rather than jam the wavelengths, the correct thing to do is set up a local cell which is strong enough to make all the cellphopnes in the area bind to it.

Eg in a theatre, the cell could act as a normal relay outside performance times, but suddenly become a black hole when the performance starts. (obviously it has to pretend still to be working, or the phones will just use another cell)

Such a system could allow emergency calls while blocking anything else.