Google and Facebook begin offering privacy features while Twitter turns on public photo sharing only.

Facebook got attacked, hard and effectively, from two fronts today. Both Twitter and Google announced new features that compete with Facebook’s killer service: photo sharing. Worse, they attacked it in the very two places it shows weakness: Twitter just made public photo sharing a cornerstone of its experience, while Google+ made sharing with small groups (like your family and select friends) both easier and more effective. All told, it probably wasn’t the best morning in Menlo Park today.