Highly controlled surveillance (e-communication, cameras etc) is rightly an important part of crime fighting and is vital to protect our society from people who wish us harm.
However, it needs to be strictly controlled and we need to stop the "purpose creep" where monitoring techniques designed to control one threat are, after commissioning, used to monitor behaviour they were never intended for.
To start with, we need strict legislation that says precisely how data can be used from different devices. Uses which aren't approved should be prevented by physical design of the devices and / or networks or, if this can't be guaranteed, the devices should not be installed.
There are way too many security cameras (to name only one method of surveillance) 'collecting data' the use of which is too loosely regulated. This is a silent tumour eating away at our democratic rights and providing the basis for the flourishing of evil. Sounds alarmist but repression isn't new in the world and it always has to start somewhere.
Why does this idea matter?
Protection from intrusive surveillance is a cornerstone of democracy state.
Without it citizens are at the mercy of elements of the state who, for a variety of reasons, could in future have the power to force our behaviour without consent or at least severely restrict freedoms that have taken 100s of years to achieve.
In the extreme it can lead to the creation of a police state.
We live in an age where technological developments have made what was once a remote nightmare vision something that could, if evil people were to flourish, be realised.
We have a responsibility to ourselves and future generations to control the tools and techniques which, though normally benign, could be used repressively.