The situation described in the article would require coordinating a lot of data together. I have a hard time seeing how individuals could do that properly without the institution noticing (especially considering how "Big Data" it is). It's not just cell data that you need, but also license plate scans, court records, etc. These are all fairly independent things, unlikely to be stored in the same place.
Individuals will try to exploit systems, and we should work hard to avoid things like LOVEINT happening (which shouldn't be hard in itself, but given that Snowden walked off with all those documents, the NSA doesn't seem very skilled in secure storage of documents).
If institutions work hard enough to make sure they're following the rules on document access, then it'll be harder for people to abuse, since each individual block of data is useless in itself. It would be the information equivalent of N keys to launch the nukes. Abuse would be much,much harder if somebody sat down and chmod'd some folders properly (nobody should have access to everything in any system). A plus side (for gov'ts at least), would be that Snowden-class events would be a lot harder to pull off.
Institutions can be built to be a lot harder to corrupt.