Google+, which has been in field trial mode since June 28, hit its first major bug over the weekend: Users were receiving duplicate email notifications, with Google sometimes sending dozens of redundant messages for a single on-site action.
Over, and over again. Yikes.” He openly accepted that Google was at fault, stating that, “We didn’t expect to hit these high thresholds so quickly, but we should have. […] Once again, we are very sorry for the spam.”
http://searchenginewatch.com/article/2093354/Google-Beta-Hits-First-Major-Bug