This is a problem inherent in the product. If you install monitors and someone else receives the data (whether a cloud provider, a camera manufacturer or a security monitoring company), then you have to trust that someone else to be responsible with the data.
Some companies with a long history in the monitoring business (like major alarm companies) can probably be trusted because they have a long history of being trustworthy. Others are too new to know if they can be trusted. And some (like social media companies) have proven themselves untrustworthy in other areas and should therefore not be trusted here.
Personally, I would never trust another company with this information. I like the idea of security cameras that record my home and can be accessed remotely, but if I ever decide to install such a system, it will be a home-grown system where the videos get recorded to my own equipment and where I access it using my own VPN LAN-access software. Because I think the only trustworthy companies charge too much money for their services and I would never trust the cheap ones.