Moves are now afoot to place the trade in surveillance technology on a similar footing to the trade in weapons. But on the assumption that export controls will never entirely stop it, some people are focusing on ways of training people to protect themselves.
"We see people making simple mistakes," explains Stephanie Hankey, co-founder of a Berlin-based group called Tactical Tech, which trains activists, journalists and civil society campaigners to become more security aware...
...She also advises people to be aware that even if the content of their conversations may be encrypted, the metadata about the conversation can reveal much about connections and patterns of activity, especially when different elements of the digital trail we leave behind are cross-referenced and cross-mapped - how we move around a city, pay taxes, cross borders and use our credit cards, as well how we communicate.
"If we piece all these things together, this tells everybody about my behaviour," says Hankey...
...But at London's IP Expo 2015, where all the talk is about the huge and mostly beneficial power of Big Data, veteran cyber security expert Mikko Hypponen, believes we are at the beginning of an enormous social change that carries with it real danger.
"We are the first generation that can be tracked from birth to our deathbeds, where we are, what we do, who we communicate with, what are our interests. It's easily trackable and saveable for decades. It feels like we're in a massive experiment done on mankind. Only much later will we realise what it means when all of our thoughts and movements not only can be tracked but are being tracked."
So will Big Data lead to Big Brother? Not necessarily - and in some countries we may have the chance to decide. But there are parts of the world where a dictatorship of data - of the type the Stasi could only dream of - may be taking shape.