Here is an interesting article from the Globe about a privacy issue brought up in B.C last week.  Basically, some environmental and aboriginal groups that are opposed to the Enbridge oil pipeline are accusing federal law enforcement of spying on them.  The B.C. Civil Liberties Association filed complaints with oversight agencies for the RCMP and Canadian Security Intelligence Service (CSIS).  The concern is that this information was shared with the oil industry and National Energy Board.  By contrast, the Natural Resources Minister stated that he understood why police might be interested in the actions of protest groups.

I think this highlights one of the bigger difficulties with privacy as it concerns government actors.  It may need to be balanced against other concerns like civil order and national security, but because privacy violations generally aren't known to the victim, it seems to be the data collector that gets to decide where that line is drawn.  Enter the whistleblower, I guess.