Limiting the exercise of power is the goal. The police by design are supposed to meet a high standard of evidence for the use of their power to be justified. The reason for this should be obvious: unrestrained power leads to very bad effects.
Before any technology or policy is used, it first needs to be considered as a weapon, because the historical record shows that this is how powerful tools end up being used regardless of how they were intended to be used. Denying law enforcement any evidence that doesn't meet specific standards isn't the way it "should be", it's the least worst way we know of having functional law enforcement without letting it devolve into various types of oppressive police states.
Whose innocence being questioned here? The quote is a non-sequitur in this context, unless you consider "being on camera" a punishment reserved for the guilty. I have bad news for you, if you've ever set foot inside a supermarket, drugstore, fast-food restaurant, corporate office, etc.
> if you've ever set foot inside a supermarket, drugstore, fast-food restaurant, office, etc.
All of which require a warrant before they can be used as evidence against you.
You're conflating private recordings that are not generally available to the enforcement power of the state with the state regularly gathering evidence against you without cause. The entire point of "innocent until proven guilty" is that there must be an established due process of law in the application of the power of the state.
For supermarket cameras, that's the warrant requirement before police can look at the recording, which creates a legal paper trail documenting their justification for needing to see the recording (which can be challenged later in court), and limits the scope of seized recordings to those at lest theoretically involved with a specific incident.
All of which require a warrant before they can be used as evidence against you.
If you are talking about the US, I think you are mistaken. While a warrant would usually be required to compel the store to provide the videotape to the police against their will, the store can always choose to provide it voluntarily. Once the prosecution has a copy of the video, they can use it as evidence whether or not there was a warrant.
Police only need a warrant (or other court order) to look at private camera recordings if the owner demands it. Most supermarket managers will happily hand over anything the police ask for.
Before any technology or policy is used, it first needs to be considered as a weapon, because the historical record shows that this is how powerful tools end up being used regardless of how they were intended to be used. Denying law enforcement any evidence that doesn't meet specific standards isn't the way it "should be", it's the least worst way we know of having functional law enforcement without letting it devolve into various types of oppressive police states.
> what's the basis?
"Innocent until proven guilty."