it's wireless so it transmits and that transmission can be received and your phone can receive a wireless signal back. That's basically how it works. They would have to know your wireless password but it would be possible to hack your phone via the wifi. I never have my wireless or bluetooth, which is also a wireless system, turned on unless I am going to use them. I think bluetooth is more of a danger in that respect as, unless you have changed your pairing code which most do not do, then anyone can access your device by pairing it and using the default code, usually 0000 or something equally easy.