I didn't mean to make an accusation, I just wanted to say that you "could" given your resources. So I guess the question is why should I trust you over a competitor?
Because the traffic that passes through our network isn't ours. It's our customers' traffic. If we start to track their customers they are going to be pissed and go somewhere else. It's not in our interest to track people, it's not how we make money and it's not our mission.