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Comment by SkyPuncher | Hacker News Reader

People don’t do it because it’s a quick way to land in hot water with the FCC.

You don’t want federal crimes because you jammed someone’s wifi

Jamming 2.4 GHz spectrum is unlikely to ever warrant an FCC response.

Virtually every microwave I've tested is an excellent jammer for 2.4 GHz. It even has a user interface for how long like you'd like to jam communications!

I'm legally allowed to "jam" your WiFi so long as I am using the spectrum for communications because I am licensed user unlike the majority of 2.4 GHz users. Even if you file an FCC complaint they aren't going to do anything.

Now if you move up to 5+ GHz range it really depends. If you start jamming the DFS bands it'll eventually get noticed.

Unless it's a very old microwave it should not be leaking RF into the surroundings because that RF is energy targeted at warming up food and liquids.

I bought my microwave in 2014. It was top of the line. I warm up a cup of water and I can watch every 2.4 GHz device drop off from my AP for that time period.

You have a defective microwave, you may want to get that checked out.

that RF is energy targeted at warming up food and liquids.

By pumping microwave energy into the water molecules. At around 2.45GHz[1]. So it doesn't take much drift and crappy shielding to crap all over adjacent spectra. This is extremely well documented and "they should build better microwaves" hasn't reached give-a-shit level for most of the world.

[1] https://iopscience.iop.org/article/10.1088/0031-9120/39/1/00...

Hell, one of my customers had one of the best 2.4GHz jammers I'd ever seen at their house. It was one of those portable handsets for hardwired phones that were still common in the 2000s before everyone started ditching land lines.

They had lots of complaints about the quality of wireless they had in their house. I dropped in more access points even after everything worked perfectly when I was there. Then they got a call when I was there and everything stopped working. This was before 5GHz was really common, but B/G/N would just stop functioning.

Last apartment I lived in (long ago), I switched pretty much everything WiFi to 5GHz (11a...not the fancy stuff we got now) when one of the neighbors bought an off brand Chinese baby monitoring system that clearly wasn't playing by the 2.4GHz rules and shit all over the spectrum. I probably could have gone the FCC route, but it wasn't them it was the guy with the dodgy microwave or whomever moved in next and 5GHz solved the problem.

I wasn't aware you could be licensed for 2.4 GHz broadcasts. What's the process on that, and what does it allow you to do? (Besides jamming others I guess)

They're probably talking about having an amateur radio license. You just need to pay $35 and take a test, nothing else is required. The test question bank is open so you can pretty trivially memorize enough of it to pass, though given that the tech license is mostly regulatory, that's equivalent to studying.

http://www.arrl.org/getting-licensed

If you do that though, you get a bunch of bands from DC to light where you can argue with old people about gout and the government.

As others have mentioned I have an amateur radio license. About 50 MHz of our allocation overlaps with the 2.4 GHz band used for WiFi. I think there is some overlap with the 5.x GHz bands as well.

You can also petition the FCC for an experimental license provided you have a valid reason. It isn't uncommon to see experimental licenses with allocations like 2 MHz - 60 GHz provided no transmission is 24/7 or unattended.

How is the FCC going to know I jammed my neighbors wifi? This is a serious question, you can practically run any red light you want where I live without any repercussions.

Is there an FCC overlord watching these signals?

This is taken a lot more serious than running red lights, and yes, they will get you. A guy in Florida was using a jammer in his car to block phones when he was driving. They found it.

https://www.pcmag.com/news/fla-man-fined-48k-for-jamming-cel...

That guy was not jamming WiFi

Also he ran the jammer every day along a very specific route. It's like robbing the same liquor store 3 nights in a row. Eventually even the laziest cop just waits around back for you to show up.

https://www.fcc.gov/over-air-spectrum-observation-capabiliti...

https://www.mdarc.org/regulations/fcc-monitoring-stations

https://www.youtube.com/watch?v=FcKCMfVJohI

Those are all either offline or too far from anyone to be able to detect, let alone triangulate, a wifi jammer.

Two ways

First way, they get reports from people/companies/band users and will maybe act on them. This assumes it's in a band they care about, people report stuff in the ham bands all the time but they nearly universally ignore those.

Second way, you interfere with something safety critical, such as an airport, where they may have installed equipment to monitor RF in particular bands.

TL;DR: unless your neighbor is an RF professional and can determine that they are being interfered with instead of "huh, the wifis no workie...shrug", they just won't do anything.

Huh? Breaking into someone’s house is already a felony pretty much everywhere.

I think it’s more likely just a bit harder to find a known good RF jammer than a rock. And a rock was usually fine. Or used to be, anyway.

Facebook tries to sell me RF jammers pretty much nonstop.

Aliexpress sellers will happilly mail you whatever RF jammer you want.

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