To quote the begining of this article from the BBC

“Welcome to the future, where everything about you is saved. A future where your actions are recorded, your movements are tracked, and your conversations are no longer ephemeral. A future brought to you not by some 1984-like dystopia, but by the natural tendencies of computers to produce data.

Data is the pollution of the information age. It’s a natural by-product of every computer-mediated interaction. It stays around forever, unless it’s disposed of. It is valuable when reused, but it must be done carefully. Otherwise, its after-effects are toxic.”