Letter Re: Cell Phone Blocking/Masking

Hi James,

For people with cell phones having non-removable batteries, I have wondered if cell phone tracking could be blocked by removing the sim card. I have such a phone, and although removing the battery is not an option, removing the sim card is pretty straightforward. – B.G.

o o o

Dear Editor,

I work exclusively with cell phone RF protocols (4G/LTE, Bluetooth) and can say this “evidence bag” does the trick. http://a.co/7z56VAh

In a separate item please let SurvivalBlog readers know that Polar Pure is back on the shelves in the USA after resolving its conflict with the geniuses at the DEA. This is year-old news, but somehow I missed it. – D2 in AZ

HJL’s Comment: Just make sure you’re turning your cell phone off when you place it in an RF shield. Without that, the phone will continue to search for service, shortening your battery life.