When it comes to Quantified Self technology such as MyBasis, having higher storage capabilities is very useful. Ideally you want to store information such as skin conductance at 1000 data points per second.

There are many times when sensors and camera's aren't that expensive and you could store a lot more data when you would have enough storage.

The limit to data retention of London surveillance videos isn't privacy law but cost of storage space. Even if private consumers have no need for diskspace companies want to do big data and need storage space.