考查事实细节。根据题干信息定位到文中第三段The digital bread crumbs (碎屑) you leave everywhere make it easy for strangers to reconstruct who you are, where you are and what you like. In some cases, a simple Google search can reveal what you think.我们在使用高科技时留下的点滴信息都会为陌生人了解我们提供线索，比如我们使用简单的Google 搜索都会暴露我们在想什么。由此可见作者之所以说we live in a world where you simply cannot keep a secret 就是因为我们在使用高科技的时候会留下痕迹。04.What do most Americans do with regard to privacy protection?
AThey change behaviors that might disclose their identity.
BThey use various loyalty cards for business transactions.
CThey rely more and more on electronic devices.
DThey talk a lot but hardly do anything about it.