I don't know if this has anything to do with it, but Zmodo being a Chinese company, maybe they are just used to auto-updating products without an owner's permission. I don't think consumer protection laws are strong in China compared to the USA so maybe this kind of practice is acceptable there. I would be surprised if they got any input from a legal department on whether this kind of practice would be acceptable here because I'm sure any competent lawyer would have warned them not to do this.
That being said, I'll keep my Zmodo running for the time being, but I'm starting to look for a replacement from another company. I'm very shocked how a company can apply a firmware to a customer's product without permission. What if such a firmware update had bricked the product? And I'm sure that the update would have caused an outage to apply the firmware so what if that took place when something bad happened that should have been recorded? After Zmodo does this once, they can do it again whenever they feel like it. I would like to see a clear policy from them on whether they are allowed to this anytime they want, but I pretty much lost all trust in this company.