this morning I wanna point out this interesting article: "SMS of Death"
Using only Short Message Service (SMS) communications—messages that can be sent between mobile phones—a pair of security researchers were able to force low-end phones to shut down abruptly and knock them off a cellular network. As well as text messages, the SMS protocol can be used to transmit small programs, called "binaries," that run on a phone.The researchers were able to create malicious SMS messages for each type of phone they studied. The messages affect the phones without any response from the user. Because feature phones are so common, Mulliner says, such an attack "could take out a large percentage of mobile communications."