How would you keep the footage secure? There is zero point in cameras if the HD's can just be carried off, a decent safe will cost > $1000 and be ugly as all hell.
Just because the data flows to somewhere you control doesn’t mean it has to be local.
I mean we’re firmly in hobbiest/semi-pro territory here but shipping the data encrypted to your own cloud instance or box colo’d in a local data center would be fine.