You started your question with a reference to preambles and then moved on to whether there should be prescriptive rules. My answer is that of course government officials, including the police, ultimately have a role to play under the law. The law should not be overly prescriptive, but at the same time, I think it is your role as parliamentarians to provide good guidance—maybe not overly prescriptive guidance, but good and substantive guidance—to government officials on how to exercise their responsibilities.
To have in the preamble to the Privacy Act the idea that privacy is a fundamental right I do not think is prescriptive, and I think would be good, sound general guidance to give to the RCMP.