In addition to the potential for agreements about sharing info from the server side that the sibling comment points out, there's also presumably nothing stoppin

In addition to the potential for agreements about sharing info from the server side that the sibling comment points out, there's also presumably nothing stopping the owners of the private cameras from voluntarily sharing footage with law enforcement. It's not completely implausible that the owners have them up to be able to defend against false allegations about what might have occurred in view of the cameras, but this doesn't seem nearly as likely a motivation as physical security, and barring them having some sort of private security force that they feel confident in dealing with any incidents they're unhappy with, the intent is probably to sometimes share footage with the cops.