Which? has raised fears about mobile phone security (PA) Mobile phone retailers are selling devices that could lose vital security updates before pay monthly contracts have finished, leaving them exposed to cyber criminals, according to Which?. The consumer organisation found that 48% of mobile phone deals across a range of retailers could lose security support before the end of the contract period. It warned that the lack of updates potentially left owners vulnerable to hackers who could take control of the phone and steal personal information, or even facing bills for hundreds of pounds for services that they have not used themselves.