A convenient voice mail feature has likely <A HREF="http://news.zdnet.com/2100-1009_22-5589608.html?tag=zdnn.alert">opened up many T-Mobile subscribers' voice mail boxes</A> to anyone armed with a simple hack. The attack, publicized by wireless security company Flexilis, could be used to download a person's voice messages or take control of the victim's voice mail functions, provided the attacker knew the subscriber's phone number.