A low pass filter on inputs (mic) and outputs (speakers).
The actual transmission channels can't actually carry true ultrasonic signals as they are limited to less than 22 to 24 kHz.
FM Radio to under 15kHz
Marketeers are coming up with ways to invade our privacy in the interests of serving us ads in a way that goes far beyond the dire predictions of films such as Minority Report. Security researchers are already thinking about countermeasures. Cross-device tracking (XDT) technologies allow marketeers to track the user's visited …
Don't these beacons fall foul of the ruling against the "mosquito" device for stopping kids hanging around?
They would, if it wasn't for the first rule of especially US based business: as long as nobody notices, it's considered acceptable in business terms.
When someone notices, have an excuse ready so you can continue doing it until it eventually makes it to court. When courst say "no", make sure you have already scurried away any data into another location or copied it so you can keep using it despite explicitly been told not to. And "accidentally" introduce it again, but make sure you can blame it on a rogue engineer (worked for Google's WiFi snooping, after all).
I keep hoping for someone to ask one of these ad-idiots how is "relevant" defined? Seems like it's buy something and then get hit with a zillion ads for the same damn product. Or is "relevant" have something to do with singing, dancing, blinking ads that take up half the screen or better?
Disclaimer: I do run a heavy HOSTS file and also Adblock. I've never clicked on an ad to buy something. I ignore the "ad" links in a Google search. Periodically, I drop the shields (except for 3rd party cookies just see if anything has changed. Nope. Same silly, irritating, bandwidth hogging shit.
And these ad clowns wonder why.....
"I ignore the "ad" links in a Google search."
I've noticed that avoiding ads is so ingrained in my subconcious these days that even when I am looking to buy something, I still the Google Ad links, even when it's from the supplier I'm looking for and carry on down the results list for a "proper" link.
The advertisers have made it so that I don't even use the ads when I could.
What you're doing is a good strategy. If you want something, go to the source. Clicking on an ad just flags you as a "mark", as in fool, patsy, with a great big target sign painted on your t-shirt. Avoiding ads is by no means fool proof, but why announce to world +dog that you're available for their abuse.
Somebody with more ambition than I could develop a hardware gadget to monitor the local ultrasonic acoustic spectrum for any such stealthy communications. Then advise the user and/or block (jam). It would be easy to 'Kickstarter' this.
Others could create a smartphone app to do the same thing. Using the same smartphone microphone that is supposedly capable of listening to signals this high in the acoustic spectrum.
Getting into 'The Art of War' mode, someone could write an app to issue false tracking data, on the local ultrasonic acoustic spectrum, so that advertisers would believe that I'm in the market for lady's micro-bikinis, thus dramatically improving my ads.
Getting into 'The Art of War' mode
That's actually the sad thing: this too has indeed become a war.
I think we've had it wrong all along. There hasn't been a war on terror or suchlike. The bottomline is that it's a war on common decency, on standards of conduct we always took for granted.
Well, screw that. Vive la résistance!
So many gee-whiz developments. And each one ends up being a new way for people to get scrod [past tense of... ] by that tech being trivially easy to abuse. Its reported here all the time. New tech! Cue applause! Oh, by the way it can be used to (multiple choice) steal, your identity, spy on you, track you, mine you, steal your money, pwn your car, turn your tech into a money making bot for a crime ring, etc. (casually mentioned).
"Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should."
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