US consumers are locked in a vicious circle with brands over customer experience, according to new research from Accenture. While 44% are frustrated when companies fail to deliver relevant, personalized shopping experiences, nearly half (49%) are concerned about personal data privacy as they subscribe to intelligent services designed to understand and anticipate their needs.   In fact, some say it can gives them the heebie-jeebies.   Accenture found nearly half (48%) of US consumers would us...