... with the introduction of smartphones with a camera or 3.
The thing is, this is unstoppable. So we might as well look at the advantages instead of running around like headless chickens all the time. Officers need these to prevent violence towards the officers AND the public to avoid unnecessary police brutality, now everyone IS accountable for their actions, I can't see this as a bad thing.
It's also highly unlikely that all video data will be stored for eternity because EVEN though we do have massive storage capacities, just imagine 7 million cameras with gigabyte storage all having to be centralized in some giant network, it would still take ages for any data processing to go trough that with image recognition, and there will probably be enough errors to keep an army of workers busy going through all of that.
And an extra little thing...
The only thing you can rest assure of, there are those in the public who also have survellance capabilities, heck...I had this back in the 80s and kept a close eye on those I wanted to keep a close eye on, including the law enforcers - and they were as clueless then as they are today. If you want to stay out of trouble - stay OFF the radar, because they already have ALL the dirt on anyone of you, they just don't know you exist - yet!