This seems fairly common in most countries, and I would guess the reason is for practical reasons. When police are out they have a fairly high probability to stumble onto more than just the specifics things they was sent out to do, and so they need to have access to check up people and vehicles.

What my country do (and others?) is to keep a strict records of every lookup, with different levels of auditor, some which checks every record in a shallow way and some which do random sampling with more deep checks. The punishment for misuse of the database is also fairly harsh.