Are your conversations on personal communication radios private? The short answer is, maybe. It depends entirely on the radio and emission used. When using conventional FM, the answer is no.
Anyone with a walkie-talkie or scanning receiver using the same band and channel, within range, will be able to listen to your conversations on MURS or FRS. Digital communications, such as DMR on PMR446 are more private, but not entirely. The most private communications are frequency-hopping, spread-spectrum (FHSS) technology used on the 902-928 MHz band, because your digital signal is constantly moving around and without the specific algorithm, no ne can hear you.
Another option to insure communication privacy is text messaging. Data transmission is legal on MURS, FRS, and 900 MHz. In fact, many 900 MHz and some FRS radios have text messaging capability integrated.
Text messaging adds another layer of privacy. Imagine you are sitting at a table in the Lido Buffet, and your daughter is at the pool on the other end of the cruise ship. You are both using 900 MHz handhelds, so your communications is encrypted through the airwaves, but anyone at the pool or in the restaurant can hear that you are dining and will meet her in the stateroom in two hours. With text messaging, you can convey the same message more securely, and this applies both onboard and on shore.
Many manufacturers advertise their radios feature Privacy Codes, but they don’t actually encrypt your.conversations. They are actually sub-audible tones which accompany your transmission which activate the receiver on radios tuned to the same sub-audible tone. Motorola refers to these as PL or Private Line tones.
In summry, there are different levels of privacy available in personal communications. There is a form of privacy that allows you to listen silently, without being bothered by the conversations of others on the same channel (by using Privacy Codes or PL Tones), a form of privacy that makes it difficult or impossible for others to monitor your conversations over the airwaves (digital or frequency-hopping, spread-spectrum communications), or a form of privacy that allows only the sender and recipient to know the contents of the message (text messaging). If privacy is important to you, you have choices and options.