Not if the phone is turned off.
Wrong...the battery has to be removed....it is still on if it is off...
They can do a lot this even if you turn the phone off. You have to pull the battery http://abcnews.go.com/blogs/headlines/2006/12/can_you_hear_me/ and that’s an old article
They can turn on any smart phone remotely, and the camera too. If you have On-Star or a similar program in your car they can do the same thing with that. With the older phones you can take out the batteries, but newer devices don't even let you do that. Your tablet and PC can also be turned on to listen if you have a microphone/camera. And, of course we have all recently learned how newer model cars can be manipulated remotely.
In facilities that handle classified material people aren't allowed to bring in phones, period, and they will use dogs to smell for the cell phone batteries to make sure that rule is enforced.
And for those of us who don't care because we never do anything wrong, remember they can always use the old trick of mixing and matching your words to have you saying things you never intended, like the way they used to fake photographs. Also, what is “wrong” for one period of time under one form of government can radically change over time. As we see now, even advocating for fair elections and
cleaned-up voter roles can get you targeted adversely by the FBI and IRS.
Nope. You have to pull the battery.
This is the reason why you can't remove the battery on the newer phones.
Are you willing to bet your freedom on that particular point?