From a security perspective, won't it be a worry? People seem to be putting so much data online without worrying about its implication --- FB, Google Docs, etc.

From a security perspective, won't it be a worry? People seem to be putting so much data online without worrying about its implication --- FB, Google Docs, etc. Toolbars, plug-ins, etc., are installed without a second thought, giving them access to your 'personal' data/habits, etc., that is not online but in your system.