People do this all the time with routers. The FCC has been trying to require firmware signing but it has been pushed off for now because there is very little demonstrable harm.
I can go buy a bunch of passives off of ebay and make a noisy oscillator that will kill everything for a couple blocks but nobody seems to do it.
I have seen the "very little demonstrable harm" you mentioned with my own eyes in real time. It was little more than serendipity that saved lives that day. If someone did do what you described then IMHO they would be recklessly endangering the lives of others and should be treated accordingly.
1. How far off the bell curve do we need to go? Do we trade all rights to do anything for diminishing returns in safety?
2. These modifications are happening right now. Bad instances are usually caught by EMS system tests or by people reporting gaps in cell coverage, etc, and are generally purpose build jammers. There are not many instances of frequency overlap. For most goods, especially consumer telecommunications equipment, other bands are protected by the fact the equipment is given a specific range to operate in anyway.
I am having difficulty working out what your position is here. Before you were talking about taking out multi block areas. Now you're talking about consumer equipment that is prevented from interfering with other frequencies. I was objecting to the former -- wherever you choose to draw your line, clearly interfering with safety-critical communications over a wide area should be well past it. The latter is a prudent step for mass market consumer goods.
You're new here, so I will gently point out that this isn't Reddit and it certainly isn't Slashdot. Asking everyone for proof of everything or implying that they are shilling is boring and unconstructive.
I've been on HN for more than a decade. You can check my comment history to see that I contribute sensibly. I have no reason to make anything about this up, but I'm obviously not going to doxx myself by providing the kind of proof that would be convincing. You're free to take me at my word or to disbelieve me, but if you aren't interested in substantial discussion in good faith, please consider simply ignoring a comment and moving on to something that interests you more.
OK. You might like to consider adopting a less confrontational tone when commenting on HN in that case, as it generally doesn't go down well here.
The answer to your question is that I once spent some time working with a network operator and on a day when I happened to be around their operations centre there was an active incident like this.
If memory serves, it turned out that the rogue device was a relatively new model that a customer had bought and was trying to use normally but something wasn't reliably operating within spec. That model would have had to pass certification to be permitted on the network but apparently this specific unit had drifted and as a result it was dumping bad data all over a control channel that was in use across a large geographical area, causing severe disruption to connectivity for everyone.
At that time some safety-critical services were using this network for communications in the field so this kind of outage was a very big deal. There were multiple vehicles with detection equipment on the road, systematically trying to narrow down the source of the interference, but of course they had trouble coordinating with the operations centre themselves because of the same disruption. I don't know everything that was going on, but I did learn that in my country there is a legal power to gain access to premises in this kind of situation and it sounded like the required formalities and officials were being arranged just in case.
As I recall, it took most of an afternoon to track down the source of the interference and get it switched off. In the end it was mostly dumb luck that it was found. I didn't quite follow what happened but possibly a detection vehicle that was out of contact with the operations centre had decided to patrol in its area until it could find another way to call in and while it was doing that it drove right past the building where the rogue unit was located and its detection equipment lit up like a Christmas tree.
The customer was entirely innocent and had no idea it was their unit causing all the trouble nor any reason they should have known. I don't know exactly what happened to that model, the manufacturer or the certification process it had managed to pass despite the defect. For sure there were serious repercussions.
This all happened some time ago and the protocols and networks have since changed but the physics hasn't. That's why I have such strong views about regulation and only allowing people who know what they're doing to have full control over transmission equipment. As the above incident shows, things can still go badly wrong even without that. If there had been a major incident requiring coordination between first responders in the field during that downtime it could have been disastrous. Minimising the risk of similar failures due to carelessness by someone who didn't fully understand their equipment and the systems and protocols they were working with just seems like common sense to me.
Which assertion is that? My contention since my very first comment has always been that messing around with radio transmission when you don't know what you're doing is dangerous. My anecdote was an illustration of what actually happened when incorrect transmission broke a system for real, how dangerous the situation became, and how difficult it was to fix.
Maybe you disagree but I think the fact that the cause of the incorrect transmission was a hardware fault in that particular anecdote is relevant only if we don't think a user with the ability to freely modify firmware as we were discussing could cause exactly the same effect either negligently or maliciously. Otherwise, the argument being made is merely that not many people actually modify firmware in dangerous ways, in which case I refer you to the nuclear analogy in my original comment.
The problem is, the kinds of problems caused by modification of the radio and a manufacturing mistake can be totally different and so things that you encountered you wouldn't see if someone simply modified it to operate on a different frequency. Therefore, your story which hinges on this difference not existing doesn't hold up.
Actually, if you had reconfigured a device badly and it had ended up signalling incorrectly on a network's control channel as a result, the situation I encountered is exactly what you would have seen on that day. Do you understand what a control channel is and why it is relevant here?
I'm thinking of if the radio had a component failure/missing and the wave it produced was either amplified or modified to be something like a square wave. It would be hard to do the latter with a simple software mod but easy with hardware.
The point is that exactly the same outcome could be caused by intentional modification. As I said in my reply to bluGill earlier, the goal is not to eliminate all risk of interference, but to reduce the risk as much as reasonably possible by controlling the potential sources where you can. Given that interference potentially causes catastrophic loss of life in this scenario, not to mention inconvenience to huge numbers of people, that seems like a good idea.
Put another way, you're not trying to prevent people who know what they're doing and follow robust processes from developing radio transmitters, even though in extreme cases such as my anecdote that might still not be enough to prevent a system failure. Nor can you realistically stop a sufficiently resourceful adversary from using radio interference as a form of attack. What you can do is stop an enthusiastic newbie who read an article about radio once from accidentally causing people to die because their experiment meant emergency responders at an incident down the street couldn't talk to each other except face to face.
I can go buy a bunch of passives off of ebay and make a noisy oscillator that will kill everything for a couple blocks but nobody seems to do it.