Readers who for whatever reason would not like to have their whereabouts traceable at any particular time should leave their cellphones at home.
The Warren Times Observer ran an Associated Press article on July 10 reporting that law enforcement surveillance requests to cellphone carriers are significantly increasing. One of the ways agencies spy on cellphone users is to look into their "ping" data.
Every few minutes your cellphone "pings" the nearest cellphone tower. One purpose of pinging is to automatically update time, date, etc. This is practical.
However, these cell tower ping data are archived by your carrier and not purged. Therefore, your cellphone is also in essence a tracking device that will tell those whose business is decidedly NOT, in fact, to know where you have been every minute of the day exactly that if they wish! There is no reason to indefinitely archive ping data other than to retain the option to trace a cellphone user's whereabouts down to the closest cell tower at any time in the past just in case someone in some agency decides they want to spy on you at some point.
If you speak with your cellphone provider and politely ask them to permanently purge all ping data for your account they will not honor this perfectly reasonable request, and they will tell you that they have a "legal right" to retain this personal information. This is in fact a flagrant violation of the 4th Amendment to the U.S. Constitution against illegal search and seizure.
Readers should never let anyone make them think that it is ever the business of cell carriers, the police department, the sheriff's office, or any government agency to know which cell phone tower you were closest to. Under any circumstance for any reason.
Beware of the lie that "if you're doing nothing wrong then you shouldn't worry that the government can spy on you."
We as a society are sliding rapidly down a slippery slope toward a ubiquitously Orwellian police/surveillance state in the name of the tiresome "fighting terrorism" canard.
If you would prefer not to have their whereabouts traceable at any particular time to simply turn off their cellphones and leave them at home. Further, in general it is best to operate at all times under the assumption that nothing you say or text, etc. on your cellphone is ever truly private. If you can manage it, probably the safest thing to do is to not even own a cellphone at all.