For Hackers, the Next Lock to Pick

Hackers have broken into the cellphones of celebrities like Scarlett Johansson and Prince William. But what about the rest of us, who might not have particularly salacious photos or voice messages stored in our phones, but nonetheless have e-mails, credit card numbers and records of our locations? A growing number of companies, including start-ups and big names in computer security like McAfee, Symantec, Sophos and AVG, see a business opportunity in mobile security — protecting cellphones from hacks and malware that could read text messages, store location information or add charges directly to mobile phone bills.