IIRC, GSM has been cracked. I'm not an expert, so I'm not sure how this affects SMS, but as SMS is done via a control channel (that was not originally intended

IIRC, GSM has been cracked. I'm not an expert, so I'm not sure how this affects SMS, but as SMS is done via a control channel (that was not originally intended to be used for text messaging), I'm assuming that there are no extra protections there. Granted, this requires physical proximity though, which definitely raises the bar for any attacker.