I just watched this TED lecture (very scary) is this ethical?
Ethical systems under which tracking such actions are considered unethical:
Given that the user must choose to use a smartphone and is in effect willingly giving up their privacy for the benefits of the system, most schools of ethics are fine with it.
Utilitarian views that this is bad for the net desire satisfaction or happiness of society would oppose it. That has to be argued, but it could be argued.
Kant argued that privacy was good because it was critical to letting people be "autonomous" which was a prerequisite for acting responsibly. Any school of ethics that argues for humans having certain properties that they shouldn't weaken or destroy could potentially include privacy as one such value.