Subscriber Discussion

Stupid Or Awesome? A Laser To Zap Thieves

As an integrator we often get humorous requests such as the one above. Even though the client is joking what they are really looking for is ACTIVE security while an intruder is on site.

We recently designed an IP camera system where the User can manually trigger several outdoor siren/strobes by the VMS. When the User receives an email alert that there is movement in front of the cameras they can use their discretion if the siren/strobes need to be activated. The User then activates via the VMS.

The Client feels like they are doing their part to fight crime and the intruder leaves and losses are reduced.

Instead of an alarm simply triggering a siren or a camera triggering an email, what's the best ACTIVE security solution you came up with?

I once had a customer ask how much a brown note generator cost, for a ensuring standoff distance from a building. Thankfully such a device is not real, because it was awkward.

There is a feature with VideoIQ for example that has (2) way audio and you can talk down through the VMS to a loud speaker. That is a cool deterrent. Another customer of mine put up blue strobes as well once the alarm analytic tripped. There is also a device I've installed recently called Redscan from Optex that puts out and 100 ft radius invisible laser. This can detect the exact location of the person for video verification.

I really like this idea :)

Fog Machine

Very active solution

That 's indoor only and small areas :2 mn fog. In an industrial plant, professionnal robbers know they have time to open windows to clear it up before police come. I thought you were talking how to prevent people from intrusion by discouraging them. Fog is a second level, like indoor alarms.

We have an extensive discussions of the pros and (mostly) cons of using fog machines here.

Yes, this is not high security. Here in France Shop keepers can't use personal weapons like you in US, and find in that type of devices a way to discourage violent attacks when video or alarms aren't suffisient anymore to prevent from agression.

I also get this type of request from time to time, mostly from angry small business people who have just been burglarized.

Back in the 70's, there was a device being sold that could dispense tear gas when an alarm was triggered. You simply took two police-sized tear gas cannisters, removed the nozzles, and placed them in the machine. There was a giant solenoid that pushed the cannisters forward to dispense the gas.

As I recall, there were many concerns about liability and clean-up with these devices. Also, the question was raised about what would happen to firefighters if they needed to respond to the building and activated the device.

Obviously something that I did not recommend.....

Perhaps a hybrid system would be be most active:

1. Fog. immediately after intrusion

2. Lasers. 2 secs post, low power 5mw red, i/o port driven, mounted underside of ptz camera with auto track or guard tour capabilities

3. Pink Floyd. thru 2 way audio, 5.1 setup thru 6 cameras ideal. Used to generate psycotic episodes in baby boomers.

Cameras could be dual visible/thermal sensors.

normally low power lasers are useless but since the place is fogged up it'll look like the departure time on the millenium falcon.

cameras of course could be manually operated for maximum user enjoyment.

call your clients bluff with this one...


This guy designed an 'active defense system' so he can shoot people over the Internet.

USB not Firewire... hmmm...

I'm sure he will get some cats that way and may be some kids if lucky :-)

It's not Pink Floyd, but can anyone vouch for the effectiveness of 'selective acoustic' tone devices like this?

Supposedly, teenagers can hear the frequency, but older folks cannot.

There's actually an iPhone app for this called StealthTone. I'm 36, and I can only hear it if I put it right up to my head, and then it's very faint. My wife is 35 and can't hear it at all. I have 7 kids, the oldest is 15. When I turn it on, they freak out, cover their ears, and tell me to turn it off. I've tried doing it at random times to make sure it wasn't a placebo thing, and they can always hear it.

We're getting old, my friends.

The Mosquito (called SonicScreen in the US) won the 2006 Ig Nobel prize for Peace (see Awards).

According to that wikipedia link, there has been some opposition to the device over the years, as some claim it violates human rights and could legally constitute an 'assault'. The 'Council of Europe' (whoever that is) voted to ban the device, but no country has ever actually done so. In the UK (where they have lots of these things), the Police Minister specifically said they would not ban the Mosquito.

IMO, if it was any other group (who actually had representation in the law making process - kids do not) it would already have been banned.

Imagine if McDonalds became annoyed with all the old folks hanging out in their restaurants, each nursing a small coffee for 4 hours. If they installed a sonic device that emitted annoying sound waves that only people over 65 could hear, the AARP would be picketing McD's headquarters within 24 hours.

I have also tested this frequency (I downloaded a file called Teenbuzz) and can confirm it works. The problem is that in deployment, old folks like us could unwittingly force a baby or pet animal to endure the noise while in the area. My teenagers confirm for me it is quite unpleasant.

Fog can be a liability problem if the intruder(s) can't get out, or get injured on the way out. I have a customer using fog machines at multiple locations in Mexico, but his attorneys in the US won't even consider it.

Strobe lights and sirens could be annoying enough that someone would want to leave.

Then there's that whole "calling the police" thing. Oh, wait -- I'm from Detroit, so never mind.

mosquito update from Gizmodo

There is growing criticism of Philadelphia officials’ decision to install sonic devices called the Mosquito that constantly emit extremely loud, high-frequency noise from 10:00 p.m. to 6:00 a.m. every night designed to be audible only to persons aged 13 to 25, according to a Friday report by NPR’s Morning Edition.

The working principle behind the devices, produced by Vancouver-based Moving Sound Technologies (MST), is that older people cannot hear such high frequencies due to hearing loss from ageing and noise pollution, though that is far from universal. The Mosquito emits an awful sound in the 17.5 to 18.5 kilohertz range that is supposed to disperse potential troublemakers to at least 130 feet. It is supposedly inaudible to most people over 30; in 2005, the New York Times described an active Mosquito as like “someone had used anti-teenage spray around the entrance, the way you might spray your sofas to keep pets off,” adding those who could hear it said it is “extremely annoying”


Tear gas is not optimal because of the extensive clean-up of residue that has settled on all the surfaces in the space.

An issue with any automated "punishment" system is the certainty that someday it's going to attack a friendly. These events must be survivable without long term adverse effects.

I'm not advocating any approach, but I can imagine PTZ pepper spray as being viable in some areas.

In some US localities, pepper spray in a purse constitutes carrying a concealed weapon. If your locality is more tolerant, I see a new use for PTZ gimbals with solenoid activation.... Even though exposure can ruin you day, this could work if coupled with reliable moving object tracking. Your most effective use would likely be the controlled lighting and environment of an indoor space, although it might annoy you to come home to clean up pepper spray that tracked the afternoon sun across the floor.

"Thanks for letting me know to pack my gas mask (that I stole from your shop last week) when I come to rob your store again" - Random Orlando thief

Wow, that video has got to be 20 years old...

In maritime environment we used to use the LRAD which is a very loud acoustic source, as well as light "dazzlers" that would make it uncomfortable to continue intrusion.

I'm disappointed to hear the brown note was a myth, as I heard it discussed.

In another country I once saw what was essentially an M-16 on a PTZ that the operator could point and fire remotely. My guess is that it would be frowned upon in the USA.