> Tracking, as we know, gives companies and governments dangerous power; the intimidating effect of general surveillance has been measured and is massive. The r

> Tracking, as we know, gives companies and governments dangerous power; the intimidating effect of general surveillance has been measured and is massive. The rate of visits to some Wikipedia pages – those about “al-Qaida”, “car bomb” and “Taliban” – declined by one-fifth after Edward Snowden showed us how much the US government spies on our internet activity.