Do you expect every recording, video, audio, and statement made by a police officer involved in a case, at any point in his service, and unrelated to the crime at hand, to be provided to the defense?
Going through someone's history to find dirt is the definition of a fishing expedition. With enough footage, speech, and actions, you could find incriminating evidence on anybody.
If there's accusations that a police officer is dishonest, lying under oath, planting evidence, or really anything else illegal, then internal affairs should be investigating them. They'd require a warrant just like anybody else to get access to the historical records (and I think they should get it). But not just any random person that wants to dig dirt on Officer Joe because he busted him for public urination.
I don't understand this objection. Police officers are generally presumed to be honest by jurors. If there is evidence that this presumption is unreasonable, then it is definitely relevant.