Is a privacy key not sufficient?
I mean I got a set of the midland radios, and I get it...if someone happens to be on the same channel/privacy key combination, they could pick you up....but what is that likelihood?
Calling a CTCSS tone a "privacy" tone is nothing more than a marketing gimmick. Yes, absolutely, no doubt about it, anyone with a FRS radio can hear your transmission, even with a "privacy" tone. All this tone does is open the squelch of the receiving radio when it hears a given tone and if that function is turned on. If you have a FRS radio with no tone squelch turned on, you can hear anyone and everyone transmitting on that "channel," whether or not they are transmitting a tone. So, if you're using one of those FRS radios, leave no doubt, people are listening.
What that tone will help you do is minimize people trying to transmit and mess with you. They can transmit and you won't hear it unless they are using the correct tone. Finding the correct tone takes no more than a few minutes and any 12 year old can do it. They will then not only listen to you, they will talk to you!