Here is an interesting article: https://theintercept.com/2020/09/25/surveillance-sim-cloning-protests-protect-phone/
I have 2 other suggestions:
- Leave your phone at home.
- Use an Apple iPod touch instead of a cell phone as it doesn’t have a SIM card and is nearly impossible to wire-tap or even detect by normal methods (see the previous article, The Most Secure Way to Communicate? An iPod Touch, at https://privacyblog.com/2015/08/20/the-most-secure-way-to-communicate-an-ipod-touch/. The primary drawback is that the iPod touch can only initiate or receive calls or text messages over wi-fi. There are several methods of carrying a wi-fi gateway with you although none of the methods I know of are convenient. Still, if privacy is important to you for business reasons, for political protests, or for any other reason, your needs might be worth the inconvenience.
- Facebook Warns Privacy Rules Could Force It to Exit European Market
- Are Encrypted Messaging Apps Really Secure?
Better yet, if one is concerned about being tracked and monitored by the constabulary, don’t use a cell phone. No one needs it, we got along just fine without it ever since Alexander Graham Bell shouted into his first instrument.
My wife and I (in our seventies) have never had a cell phone, never needed one, can’t imagine what we would use it for. There’s no call so important that it can’t wait till you get home and use the telephone safely wired to the wall where it belongs.
I agree with much of what you say, but will also point that (old-fashioned) wired telephones are the easiest phones to wire-tap. Not only can the police do that, but any neighborhood 12-year-old with an earphone and alligator clips can tap into your phone line and listen to your conversations. If I had any reason to worry about privacy in my telephone conversations, I would never use a wired telephone.
Getting stranded somewhere with an emergency?
Lack of phonebooths anywhere?
Navigating in unknown locations?
Camera at hand if you need one?
These are just a few reasons why some might need a cell phone.