We've been getting submissions about an uptick in compromised Gmail accounts in the last few days, but nothing that could be substantiated. Robert McMillan did a bit of digging and now reports in PC World that "Google is investigating a growing number of reports that hackers are breaking into legitimate Gmail accounts and then using them to send spam messages. The problem started about a week ago but seems to have escalated over the past few days. ... [I]n forum posts, Gmail users note that the hackers appear to be sending spam via Gmail's mobile interface — which gives mobile-phone users a way to check their Gmail accounts — and wonder if there may be a bug in the mobile interface that is allowing criminals to send the spam. ... Google says there's no Gmail bug. ... 'Spammers may sometimes use a mobile interface to access accounts they have already compromised because it's simpler for bots to use this method at large scale.'" Here's how to tell if your Gmail account has been accessed by bad guys, and what to do about it.