Security researcher Karsten Nohl has released a software program called Airprobe that makes it much easier for people to test security (and potentially listen to calls) on their chosen mobile network. Airprobe enables users to record and then decode GSM mobile phone calls when used in conjunction with a computer, additional radio equipment and tables of data.
However, it'll only work on networks that haven't been 'patched' to eliminate a two-year-old security loophole. Mr Nohl released the tool at this year's Black Hat security conference to prompt mobile networks operators to check and improve security.
[Sources: TheRegister.co.uk; FT.com; BBC.co.uk]