When you accumulate datasets, one of civil society's great concerns is that the data can deal with all kinds of information that is not essential to your work and that can interfere with privacy. In that sense, it may also include what the bill calls unselected data.
Technically, how do you proceed? If the court determines that you have the right to collect that information because the target is legitimate, how do you go about distinguishing the legitimate target from the unselected data that will inevitably be collected? Has a system been put in place? Perhaps my level of understanding is not as high as yours, but, when you are collecting datasets, the net is clearly cast very wide and the information is not automatically relevant to the investigations.