Researcher Karsten Nohl has told the Chaos Communication Conference in Berlin that he's compiled enough data to crack the encryption used for GSM calls and messages. This would enable anyone with a powerul laptop and a few hundred pounds of equipment to listen in to mobile phone calls.
It's a project he started in August to illustrate the flaws in GSM encryption. More information is expected on Wednesday when Mr Nohl demonstrates the current state of his research.
Nokia has followed up its recent legal action against Apple by filing a complaint with the USA's International Trade Commission.
It alleges that Apple infringes seven Nokia patents in almost all of its mobile phones, portable music players and computers.